Zoom lens system, imaging device and camera

ABSTRACT

A zoom lens system of the present invention has a plurality of lens units each composed of at least one lens element and, in order from the object side to the image side, comprises: a first lens unit having negative optical power and composed of two lens elements; a second lens unit having positive optical power; and a third lens unit having positive optical power, wherein in zooming from a wide-angle limit to a telephoto limit during image taking, the individual lens units are moved along an optical axis such that an interval between the first lens unit and the second lens unit should decrease and that an interval between the second lens unit and the third lens unit should increase, so that magnification change is achieved, and wherein on the image side relative to the second lens unit, an aperture diaphragm is arranged that moves along the optical axis integrally with the second lens unit during zooming.

TECHNICAL FIELD

The present invention relates to a zoom lens system, an imaging deviceand a camera. In particular, the present invention relates to: a zoomlens system that has not only a high resolution but also a reducedoverall optical length (overall length of lens system) and a variablemagnification ratio as high as approximately 5 and that has a view angleof approximately 70° at a wide-angle limit and hence is satisfactorilyadaptable for wide-angle image taking; an imaging device employing thiszoom lens system; and a thin and remarkably compact camera employingthis imaging device.

BACKGROUND ART

With recent progress in the development of solid-state image sensorssuch as a CCD (Charge Coupled Device) and a CMOS (ComplementaryMetal-Oxide Semiconductor) having a high pixel, digital still camerasand digital video cameras (simply referred to as “digital cameras”,hereinafter) are rapidly spreading that employ an imaging deviceincluding an imaging optical system of high optical performancecorresponding to the above-mentioned solid-state image sensors of a highpixel. Among these digital cameras of high optical performance, demandsare increasing especially for digital cameras of compact type.

In digital cameras of compact type described above, from the perspectiveof easiness in carrying and accommodation, further thickness reductionis required. For the purpose of realizing such compact and thin digitalcameras, in the conventional art, variable zoom lens systems have beenproposed that have a three-unit construction of negative lead type, inorder from the object side to the image side, comprising a first lensunit having negative optical power, a second lens unit having positiveoptical power and a third lens unit having positive optical power andthat have a reduced overall optical length (overall length of lenssystem: the distance measured from the vertex of a lens surface on themost object side in the entire lens system to the image surface).

For example, Japanese Patent Publication No. 3513369 discloses a zoomlens which, in order from the object side to the image side, comprisesthree lens units of negative, positive and positive and in which: at atelephoto limit in comparison with a wide-angle limit, the individuallens units are moved such that the interval between first and secondlens units and the interval between second and third lens units shoulddecrease so that magnification change is achieved; the first lens unitis composed of two lenses of negative and positive; the second lens unitis composed of independent two lenses of positive and negative; thethird lens unit is composed of one positive lens; and a particularrelation is satisfied by the radius of curvature of the object sidesurface of the negative lens contained in the second lens unit and thefocal length of the entire system at a wide-angle limit. In this zoomlens disclosed in Japanese Patent Publication No. 3513369, overalloptical length is reduced, and still high optical performance isobtained over the entire variable magnification range.

Further, Japanese Laid-Open Patent Publication No. 2006-301154 disclosesa zoom lens which, in order from the object side to the image side,comprises three lens units of negative, positive and positive and inwhich: the intervals between the individual lens units vary at the timeof magnification change; particular relations are satisfied respectivelyby the taken-image height and the focal length of the entire system at awide-angle limit, by the axial interval between the first and the secondlens units and the focal length of the first lens unit, and by the axialinterval between the first and the second lens units and the focallength of the second lens unit; and a variable magnification ratio thatfalls within a particular range is obtained. This zoom lens disclosed inJapanese Laid-Open Patent Publication No. 2006-301154 has a wide viewangle at a wide-angle limit as well as a relatively high variablemagnification ratio.

Moreover, Japanese Laid-Open Patent Publication No. 2006-065034discloses a zoom lens which, in order from the object side to the imageside, comprises three lens units of negative, positive and positive andin which: the intervals between the individual lens units vary at thetime of magnification change; the first lens unit is composed of twolenses of negative and positive; the second lens unit is constructedfrom a 2a-th lens unit composed of two lenses of positive and negativeand a 2b-th lens unit composed of at least one positive lens arranged onthe image side relative to the 2a-th lens unit; the third lens unit iscomposed of at least one positive lens; and particular relations aresatisfied by the imaging magnifications of the second lens unit at awide-angle limit and a telephoto limit, the interval between the firstand the second lens units at a wide-angle limit, and the intervalbetween the second and the third lens units at a telephoto limit. Thiszoom lens disclosed in Japanese Laid-Open Patent Publication No.2006-065034 achieves desired optical performance and still has a reducednumber of component lenses and relative compactness.

Patent Document 1: Japanese Patent Publication No. 3513369 PatentDocument 2: Japanese Laid-Open Patent Publication No. 2006-301154 PatentDocument 3: Japanese Laid-Open Patent Publication No. 2006-065034DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

The above-mentioned zoom lens disclosed in Japanese Patent PublicationNo. 3513369 has high optical performance, a view angle as wide as 65° to75° at a wide-angle limit, and a reduced overall optical length. Thispermits further thickness reduction in digital cameras of compact type.Nevertheless, the zoom lens has as small a variable magnification ratioas approximately 3, and hence does not satisfy a requirement in digitalcameras of compact type in recent years.

Further, the zoom lens disclosed in Japanese Laid-Open PatentPublication No. 2006-301154 has a sufficient view angle for wide-angleimage taking and a higher variable magnification ratio than the zoomlens disclosed in Japanese Patent Publication No. 3513369. Nevertheless,in this lens configuration, the amount of movement of the second lensunit along the optical axis at the time of magnification change islarge. Thus, the overall optical length increases, and hence furtherthickness reduction cannot be achieved in digital cameras of compacttype.

Moreover, similarly to the zoom lens disclosed in Japanese PatentPublication No. 3513369, the zoom lens disclosed in Japanese Laid-OpenPatent Publication No. 2006-065034 achieves desired optical performanceand still has a sufficient view angle for wide-angle image taking and areduced overall optical length. This permits further thickness reductionin digital cameras of compact type. Nevertheless, this zoom lens has assmall a variable magnification ratio as approximately 3, and hence doesnot satisfy a requirement in digital cameras of compact type in recentyears.

An object of the present invention is to provide: a zoom lens systemthat has not only a high resolution but also a reduced overall opticallength and a variable magnification ratio as high as approximately 5 andthat has a view angle of approximately 70° at a wide-angle limit andhence is satisfactorily adaptable for wide-angle image taking; animaging device employing this zoom lens system; and a thin andremarkably compact camera employing this imaging device.

Solution to the Problems

One of the above-mentioned objects is achieved by the following zoomlens system. That is, the present invention relates to

a zoom lens system having a plurality of lens units each composed of atleast one lens element and,

in order from an object side to an image side, comprising:

a first lens unit having negative optical power and composed of two lenselements;

a second lens unit having positive optical power; and

a third lens unit having positive optical power, wherein

in zooming from a wide-angle limit to a telephoto limit during imagetaking, the individual lens units are moved along an optical axis suchthat an interval between the first lens unit and the second lens unitshould decrease and that an interval between the second lens unit andthe third lens unit should increase, so that magnification change isachieved, and wherein on the image side relative to the second lensunit, an aperture diaphragm is arranged that moves along the opticalaxis integrally with the second lens unit during zooming.

One of the above-mentioned objects is achieved by the following imagingdevice. That is, the present invention relates to

an imaging device capable of outputting an optical image of an object asan electric image signal, comprising:

a zoom lens system that forms the optical image of the object; and

an image sensor that converts the optical image formed by the zoom lenssystem into the electric image signal, wherein

the zoom lens system has a plurality of lens units each composed of atleast one lens element and,

in order from an object side to an image side, comprises:

a first lens unit having negative optical power and composed of two lenselements;

a second lens unit having positive optical power; and

a third lens unit having positive optical power, wherein

in zooming from a wide-angle limit to a telephoto limit during imagetaking, the individual lens units are moved along an optical axis suchthat an interval between the first lens unit and the second lens unitshould decrease and that an interval between the second lens unit andthe third lens unit should increase, so that magnification change isachieved, and wherein on the image side relative to the second lensunit, an aperture diaphragm is arranged that moves along the opticalaxis integrally with the second lens unit during zooming.

One of the above-mentioned objects is achieved by the following camera.That is, the present invention relates to

a camera for converting an optical image of an object into an electricimage signal and then performing at least one of displaying and storingof the converted image signal, comprising

an imaging device including a zoom lens system that forms the opticalimage of the object and an image sensor that converts the optical imageformed by the zoom lens system into the electric image signal, wherein

the zoom lens system has a plurality of lens units each composed of atleast one lens element and,

in order from an object side to an image side, comprises:

a first lens unit having negative optical power and composed of two lenselements;

a second lens unit having positive optical power; and

a third lens unit having positive optical power, wherein

in zooming from a wide-angle limit to a telephoto limit during imagetaking, the individual lens units are moved along an optical axis suchthat an interval between the first lens unit and the second lens unitshould decrease and that an interval between the second lens unit andthe third lens unit should increase, so that magnification change isachieved, and wherein

on the image side relative to the second lens unit, an aperturediaphragm is arranged that moves along the optical axis integrally withthe second lens unit during zooming.

EFFECT OF THE INVENTION

According to the present invention, a zoom lens system is provided thathas not only a high resolution but also a reduced overall optical lengthand a variable magnification ratio as high as approximately 5 and thathas a view angle of approximately 70° at a wide-angle limit and hence issatisfactorily adaptable for wide-angle image taking. Further, thepresent invention provides: an imaging device employing this zoom lenssystem; and a thin and remarkably compact camera employing this imagingdevice.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 1 (Example 1).

FIG. 2 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 1.

FIG. 3 is a lateral aberration diagram of a zoom lens system accordingto Example 1 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 4 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 2 (Example 2).

FIG. 5 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 2.

FIG. 6 is a lateral aberration diagram of a zoom lens system accordingto Example 2 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 7 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 3 (Example 3).

FIG. 8 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 3.

FIG. 9 is a lateral aberration diagram of a zoom lens system accordingto Example 3 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 10 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 4 (Example 4).

FIG. 11 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 4.

FIG. 12 is a lateral aberration diagram of a zoom lens system accordingto Example 4 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 13 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 5 (Example 5).

FIG. 14 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 5.

FIG. 15 is a lateral aberration diagram of a zoom lens system accordingto Example 5 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 16 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 6 (Example 6).

FIG. 17 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 6.

FIG. 18 is a lateral aberration diagram of a zoom lens system accordingto Example 6 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 19 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 7 (Example 7).

FIG. 20 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 7.

FIG. 21 is a lateral aberration diagram of a zoom lens system accordingto Example 7 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 22 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 8 (Example 8).

FIG. 23 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 8.

FIG. 24 is a lateral aberration diagram of a zoom lens system accordingto Example 8 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 25 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 9 (Example 9).

FIG. 26 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 9.

FIG. 27 is a lateral aberration diagram of a zoom lens system accordingto Example 9 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 28 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 10 (Example 10).

FIG. 29 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 10.

FIG. 30 is a lateral aberration diagram of a zoom lens system accordingto Example 10 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 31 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 11 (Example 11).

FIG. 32 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 11.

FIG. 33 is a lateral aberration diagram of a zoom lens system accordingto Example 11 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 34 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 12 (Example 12).

FIG. 35 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 12.

FIG. 36 is a lateral aberration diagram of a zoom lens system accordingto Example 12 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 37 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 13 (Example 13).

FIG. 38 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 13.

FIG. 39 is a lateral aberration diagram of a zoom lens system accordingto Example 13 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 40 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 14 (Example 14).

FIG. 41 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 14.

FIG. 42 is a lateral aberration diagram of a zoom lens system accordingto Example 14 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 43 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 15 (Example 15).

FIG. 44 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 15.

FIG. 45 is a lateral aberration diagram of a zoom lens system accordingto Example 15 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 46 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 16 (Example 16).

FIG. 47 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 16.

FIG. 48 is a lateral aberration diagram of a zoom lens system accordingto Example 16 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 49 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 17 (Example 17).

FIG. 50 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 17.

FIG. 51 is a lateral aberration diagram of a zoom lens system accordingto Example 17 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 52 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 18 (Example 18).

FIG. 53 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 18.

FIG. 54 is a lateral aberration diagram of a zoom lens system accordingto Example 18 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 55 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 19 (Example 19).

FIG. 56 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 19.

FIG. 57 is a lateral aberration diagram of a zoom lens system accordingto Example 19 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 58 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 20 (Example 20).

FIG. 59 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 20.

FIG. 60 is a lateral aberration diagram of a zoom lens system accordingto Example 20 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 61 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 21 (Example 21).

FIG. 62 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 21.

FIG. 63 is a lateral aberration diagram of a zoom lens system accordingto Example 21 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 64 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 22 (Example 22).

FIG. 65 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 22.

FIG. 66 is a lateral aberration diagram of a zoom lens system accordingto Example 22 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 67 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 23 (Example 23).

FIG. 68 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 23.

FIG. 69 is a lateral aberration diagram of a zoom lens system accordingto Example 23 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 70 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 24 (Example 24).

FIG. 71 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 24.

FIG. 72 is a lateral aberration diagram of a zoom lens system accordingto Example 24 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 73 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 25 (Example 25).

FIG. 74 is a longitudinal aberration diagram of an infinity in-focuscondition of a zoom lens system according to Example 25.

FIG. 75 is a lateral aberration diagram of a zoom lens system accordingto Example 25 at a telephoto limit in a basic state where image blurcompensation is not performed and in a blur compensation state.

FIG. 76 is a schematic construction diagram of a digital still cameraaccording to Embodiment 26.

DESCRIPTION OF THE REFERENCE CHARACTERS

-   -   G1 First lens unit    -   G2 Second lens unit    -   G3 Third lens unit    -   L1 First lens element    -   L2 Second lens element    -   L3 Third lens element    -   L4 Fourth lens element    -   L5 Fifth lens element    -   L6 Sixth lens element    -   L7 Seventh lens element, Plane parallel plate    -   L8 Plane parallel plate    -   L9 Plane parallel plate    -   A Aperture diaphragm    -   S Image surface    -   1 Zoom lens system    -   2 Image sensor    -   3 Liquid crystal display monitor    -   4 Body    -   5 Main barrel    -   6 Moving barrel    -   7 Cylindrical cam

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments 1 to 25

FIGS. 1, 4, 7, 10, 13, 16, 19, 22, 25, 28, 31, 34, 37, 40, 43, 46, 49,52, 55, 58, 61, 64, 67, 70 and 73 are lens arrangement diagrams of zoomlens systems according to Embodiments 1 to 25, respectively.

Each of FIGS. 1, 4, 7, 10, 13, 16, 19, 22, 25, 28, 31, 34, 37, 40, 43,46, 49, 52, 55, 58, 61, 64, 67, 70 and 73 shows a zoom lens system in aninfinity in-focus condition. In each FIG., part (a) shows a lensconfiguration at a wide-angle limit (in the minimum focal lengthcondition: focal length f_(W)), part (b) shows a lens configuration at amiddle position (in an intermediate focal length condition: focal lengthf_(M)=√{square root over ( )}(f_(W)*f_(T))), and part (c) shows a lensconfiguration at a telephoto limit (in the maximum focal lengthcondition: focal length f_(T)). Further, in each FIG., each bent arrowlocated between part (a) and part (b) indicates a line obtained byconnecting the positions of each lens unit respectively at, in orderfrom the upper, a wide-angle limit, a middle position and a telephotolimit. Thus, in the part between the wide-angle limit and the middleposition and the part between the middle position and the telephotolimit, the positions are connected simply with a straight line, andhence this line does not indicate actual motion of each lens unit.Moreover, in each FIG., an arrow imparted to a lens unit indicatesfocusing from an infinity in-focus condition to a close-object in-focuscondition. That is, the arrow indicates the moving direction at the timeof focusing from an infinity in-focus condition to a close-objectin-focus condition.

The zoom lens system according to each embodiment, in order from theobject side to the image side, comprises a first lens unit G1 havingnegative optical power, a second lens unit G2 having positive opticalpower and a third lens unit G3 having positive optical power. Then, inzooming from a wide-angle limit to a telephoto limit during imagetaking, the individual lens units move along the optical axis such thatthe interval between the first lens unit G1 and the second lens unit G2should decrease and that the interval between the second lens unit G2and the third lens unit G3 should increase (this lens configuration isreferred to as the basic configuration of the embodiment, hereinafter).In the zoom lens system according to each embodiment, when these lensunits are arranged in a desired optical power configuration, highoptical performance is obtained and still size reduction is achieved inthe entire lens system.

Further, in FIGS. 1, 4, 7, 10, 13, 16, 19, 22, 25, 28, 31, 34, 37, 40,43, 46, 49, 52, 55, 58, 61, 64, 67, 70 and 73, an asterisk * imparted toa particular surface indicates that the surface is aspheric. In eachFIG., symbol (+) or (−) imparted to the symbol of each lens unitcorresponds to the sign of the optical power of the lens unit. In eachFIG., the straight line located on the most right-hand side indicatesthe position of the image surface S. On the object side relative to theimage surface S (that is, between the image surface S and the most imageside lens surface of the third lens unit G3), a plane parallel platesuch as an optical low-pass filter and a face plate of an image sensoris provided.

Moreover, in FIGS. 1, 4, 7, 10, 13, 16, 19, 22, 25, 28, 31, 34, 37, 40,43, 46, 49, 52, 55, 58, 61, 64, 67, 70 and 73, an aperture diaphragm Ais provided on the image side relative to the second lens unit G2 (thatis, between the most image side lens surface of the second lens unit G2and the most object side lens surface of the third lens unit G3). Inzooming from a wide-angle limit to a telephoto limit during imagetaking, the aperture diaphragm A moves along the optical axis integrallywith the second lens unit G2. As such, in the zoom lens system accordingto each embodiment, on the image side relative to the second lens unitG2, the aperture diaphragm A is arranged that moves along the opticalaxis integrally with the second lens unit G2 during zooming from awide-angle limit to a telephoto limit in image taking. This permitslength reduction in the air space between the first lens unit G1 and thesecond lens unit G2. As a result, in spite of being a three-unitconstruction of negative lead type, a reduced overall optical length anda variable magnification ratio as high as approximately 5 are achievedsimultaneously.

As shown in FIG. 1, in the zoom lens system according to Embodiment 1,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has two aspheric surfaces, while the second lens elementL2 has an aspheric object side surface.

Further, in the zoom lens system according to Embodiment 1, the secondlens unit G2, in order from the object side to the image side,comprises: a positive meniscus third lens element L3 with the convexsurface facing the object side; a bi-convex fourth lens element L4; abi-concave fifth lens element L5; and a bi-convex sixth lens element L6.Among these, the fourth lens element L4 and the fifth lens element L5are cemented with each other. In the surface data in the correspondingnumerical example described later, surface number 8 indicates the cementlayer between the fourth lens elements L4 and the fifth lens element L5.Further, the third lens element L3 has an aspheric object side surface.

Moreover, in the zoom lens system according to Embodiment 1, the thirdlens unit G3 comprises solely a positive meniscus seventh lens elementL7 with the convex surface facing the image side. The seventh lenselement L7 has two aspheric surfaces.

In the zoom lens system according to Embodiment 1, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 4, in the zoom lens system according to Embodiment 2,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has an aspheric image side surface, while the secondlens element L2 has an aspheric object side surface.

In the zoom lens system of Embodiment 2, the second lens unit G2, inorder from the object side to the image side, comprises: a positivemeniscus third lens element L3 with the convex surface facing the objectside; a bi-convex fourth lens element L4; a bi-concave fifth lenselement L5; and a positive meniscus sixth lens element L6 with theconvex surface facing the object side. Among these, the fourth lenselement L4 and the fifth lens element L5 are cemented with each other.In the surface data in the corresponding numerical example describedlater, surface number 8 indicates the cement layer between the fourthlens elements L4 and the fifth lens element L5. Further, the sixth lenselement L6 has two aspheric surfaces.

Further, in the zoom lens system of Embodiment 2, the third lens unit G3comprises solely a bi-convex seventh lens element L7. The seventh lenselement L7 has two aspheric surfaces.

In the zoom lens system according to Embodiment 2, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 7, in the zoom lens system according to Embodiment 3,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has two aspheric surfaces, while the second lens elementL2 has an aspheric object side surface.

Further, in the zoom lens system according to Embodiment 3, the secondlens unit G2, in order from the object side to the image side,comprises: a positive meniscus third lens element L3 with the convexsurface facing the object side; a bi-convex fourth lens element L4; abi-concave fifth lens element L5; and a bi-convex sixth lens element L6.Among these, the fourth lens element L4 and the fifth lens element L5are cemented with each other. In the surface data in the correspondingnumerical example described later, surface number 8 indicates the cementlayer between the fourth lens elements L4 and the fifth lens element L5.Further, the third lens element L3 has an aspheric object side surface.

Moreover, in the zoom lens system according to Embodiment 3, the thirdlens unit G3 comprises solely a positive meniscus seventh lens elementL7 with the convex surface facing the image side. The seventh lenselement L7 has two aspheric surfaces.

In the zoom lens system according to Embodiment 3, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 10, in the zoom lens system according to Embodiment 4,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has two aspheric surfaces, while the second lens elementL2 has an aspheric object side surface.

Further, in the zoom lens system according to Embodiment 4, the secondlens unit G2, in order from the object side to the image side,comprises: a positive meniscus third lens element L3 with the convexsurface facing the object side; a bi-convex fourth lens element L4; abi-concave fifth lens element L5; and a bi-convex sixth lens element L6.Among these, the fourth lens element L4 and the fifth lens element L5are cemented with each other. In the surface data in the correspondingnumerical example described later, surface number 8 indicates the cementlayer between the fourth lens elements L4 and the fifth lens element L5.Further, the third lens element L3 has an aspheric object side surface.

Moreover, in the zoom lens system according to Embodiment 4, the thirdlens unit G3 comprises solely a positive meniscus seventh lens elementL7 with the convex surface facing the image side. The seventh lenselement L7 has two aspheric surfaces.

In the zoom lens system according to Embodiment 4, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 13, in the zoom lens system according to Embodiment 5,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has two aspheric surfaces, while the second lens elementL2 has an aspheric object side surface.

Further, in the zoom lens system according to Embodiment 5, the secondlens unit G2, in order from the object side to the image side,comprises: a positive meniscus third lens element L3 with the convexsurface facing the object side; a bi-convex fourth lens element L4; abi-concave fifth lens element L5; and a bi-convex sixth lens element L6.Among these, the fourth lens element L4 and the fifth lens element L5are cemented with each other. In the surface data in the correspondingnumerical example described later, surface number 8 indicates the cementlayer between the fourth lens elements L4 and the fifth lens element L5.Further, the third lens element L3 has an aspheric object side surface.

Moreover, in the zoom lens system according to Embodiment 5, the thirdlens unit G3 comprises solely a positive meniscus seventh lens elementL7 with the convex surface facing the image side. The seventh lenselement L7 has two aspheric surfaces.

In the zoom lens system according to Embodiment 5, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 16, in the zoom lens system according to Embodiment 6,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has two aspheric surfaces, while the second lens elementL2 has an aspheric object side surface.

Further, in the zoom lens system according to Embodiment 6, the secondlens unit G2, in order from the object side to the image side,comprises: a positive meniscus third lens element L3 with the convexsurface facing the object side; a bi-convex fourth lens element L4; abi-concave fifth lens element L5; and a bi-convex sixth lens element L6.Among these, the fourth lens element L4 and the fifth lens element L5are cemented with each other. In the surface data in the correspondingnumerical example described later, surface number 8 indicates the cementlayer between the fourth lens elements L4 and the fifth lens element L5.Further, the third lens element L3 has an aspheric object side surface.

Moreover, in the zoom lens system according to Embodiment 6, the thirdlens unit G3 comprises solely a positive meniscus seventh lens elementL7 with the convex surface facing the image side. The seventh lenselement L7 has two aspheric surfaces.

In the zoom lens system according to Embodiment 6, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 19, in the zoom lens system according to Embodiment 7,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has an aspheric image side surface, while the secondlens element L2 has an aspheric object side surface.

Further, in the zoom lens system according to Embodiment 7, the secondlens unit G2, in order from the object side to the image side,comprises: a positive meniscus third lens element L3 with the convexsurface facing the object side; a bi-convex fourth lens element L4; abi-concave fifth lens element L5; and a bi-convex sixth lens element L6.Among these, the fourth lens element L4 and the fifth lens element L5are cemented with each other. In the surface data in the correspondingnumerical example described later, surface number 8 indicates the cementlayer between the fourth lens elements L4 and the fifth lens element L5.Further, the third lens element L3 has an aspheric object side surface.

Moreover, in the zoom lens system according to Embodiment 7, the thirdlens unit G3 comprises solely a positive meniscus seventh lens elementL7 with the convex surface facing the image side. The seventh lenselement L7 has two aspheric surfaces.

In the zoom lens system according to Embodiment 7, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 22, in the zoom lens system according to Embodiment 8,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has two aspheric surfaces, while the second lens elementL2 has an aspheric object side surface.

Further, in the zoom lens system according to Embodiment 8, the secondlens unit G2, in order from the object side to the image side,comprises: a positive meniscus third lens element L3 with the convexsurface facing the object side; a bi-convex fourth lens element L4; abi-concave fifth lens element L5; and a bi-convex sixth lens element L6.Among these, the fourth lens element L4 and the fifth lens element L5are cemented with each other. In the surface data in the correspondingnumerical example described later, surface number 8 indicates the cementlayer between the fourth lens elements L4 and the fifth lens element L5.Further, the third lens element L3 has an aspheric object side surface.

Moreover, in the zoom lens system according to Embodiment 8, the thirdlens unit G3 comprises solely a positive meniscus seventh lens elementL7 with the convex surface facing the image side. The seventh lenselement L7 has two aspheric surfaces.

In the zoom lens system according to Embodiment 8, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 25, in the zoom lens system according to Embodiment 9,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has two aspheric surfaces, while the second lens elementL2 has an aspheric object side surface.

Further, in the zoom lens system according to Embodiment 9, the secondlens unit G2, in order from the object side to the image side,comprises: a positive meniscus third lens element L3 with the convexsurface facing the object side; a bi-convex fourth lens element L4; abi-concave fifth lens element L5; and a bi-convex sixth lens element L6.Among these, the fourth lens element L4 and the fifth lens element L5are cemented with each other. In the surface data in the correspondingnumerical example described later, surface number 8 indicates the cementlayer between the fourth lens elements L4 and the fifth lens element L5.Further, the third lens element L3 has an aspheric object side surface.

Moreover, in the zoom lens system according to Embodiment 9, the thirdlens unit G3 comprises solely a positive meniscus seventh lens elementL7 with the convex surface facing the image side. The seventh lenselement L7 has two aspheric surfaces.

In the zoom lens system according to Embodiment 9, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 28, in the zoom lens system according to Embodiment 10,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has two aspheric surfaces.

Further, in the zoom lens system according to Embodiment 10, the secondlens unit G2, in order from the object side to the image side,comprises: a bi-convex third lens element L3; a bi-convex fourth lenselement L4; a bi-concave fifth lens element L5; and a bi-convex sixthlens element L6. Among these, the fourth lens element L4 and the fifthlens element L5 are cemented with each other. In the surface data in thecorresponding numerical example described later, surface number 8indicates the cement layer between the fourth lens element L4 and thefifth lens element L5. Further, the third lens element L3 has anaspheric object side surface.

Moreover, in the zoom lens system according to Embodiment 10, the thirdlens unit G3 comprises solely a positive meniscus seventh lens elementL7 with the convex surface facing the image side. The seventh lenselement L7 has an aspheric image side surface.

In the zoom lens system according to Embodiment 10, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 31, in the zoom lens system according to Embodiment 11,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has two aspheric surfaces, while the second lens elementL2 has an aspheric object side surface.

Further, in the zoom lens system according to Embodiment 11, the secondlens unit G2, in order from the object side to the image side,comprises: a bi-convex third lens element L3; a bi-concave fourth lenselement L4; and a bi-convex fifth lens element L5. Among these, thethird lens element L3 and the fourth lens element L4 are cemented witheach other. In the surface data in the corresponding numerical exampledescribed later, surface number 6 indicates the cement layer between thethird lens element L3 and the fourth lens element L4. Further, the thirdlens element L3 has an aspheric object side surface.

Further, in the zoom lens system of Embodiment 11, the third lens unitG3 comprises solely a bi-convex sixth lens element L6. The sixth lenselement L6 has two aspheric surfaces.

In the zoom lens system according to Embodiment 11, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 34, in the zoom lens system according to Embodiment 12,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has two aspheric surfaces, while the second lens elementL2 has an aspheric object side surface.

Further, in the zoom lens system according to Embodiment 12, the secondlens unit G2, in order from the object side to the image side,comprises: a bi-convex third lens element L3; a bi-concave fourth lenselement L4; and a bi-convex fifth lens element L5. Among these, thethird lens element L3 and the fourth lens element L4 are cemented witheach other. In the surface data in the corresponding numerical exampledescribed later, surface number 6 indicates the cement layer between thethird lens element L3 and the fourth lens element L4. Further, the thirdlens element L3 has an aspheric object side surface.

Further, in the zoom lens system of Embodiment 12, the third lens unitG3 comprises solely a bi-convex sixth lens element L6. The sixth lenselement L6 has two aspheric surfaces.

In the zoom lens system according to Embodiment 12, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 37, in the zoom lens system according to Embodiment 13,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has an aspheric image side surface, while the secondlens element L2 has an aspheric object side surface.

Further, in the zoom lens system according to Embodiment 13, the secondlens unit G2, in order from the object side to the image side,comprises: a bi-convex third lens element L3; a bi-concave fourth lenselement L4; and a bi-convex fifth lens element L5. Among these, thethird lens element L3 and the fourth lens element L4 are cemented witheach other. In the surface data in the corresponding numerical exampledescribed later, surface number 6 indicates the cement layer between thethird lens element L3 and the fourth lens element L4. Further, the thirdlens element L3 has an aspheric object side surface.

Further, in the zoom lens system of Embodiment 13, the third lens unitG3 comprises solely a bi-convex sixth lens element L6. The sixth lenselement L6 has two aspheric surfaces.

In the zoom lens system according to Embodiment 13, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 40, in the zoom lens system according to Embodiment 14,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has two aspheric surfaces, while the second lens elementL2 has an aspheric object side surface.

Further, in the zoom lens system according to Embodiment 14, the secondlens unit G2, in order from the object side to the image side,comprises: a positive meniscus third lens element L3 with the convexsurface facing the object side; a negative meniscus fourth lens elementL4 with the convex surface facing the object side; and a bi-convex fifthlens element L5. Among these, the third lens element L3 and the fourthlens element L4 are cemented with each other. In the surface data in thecorresponding numerical example described later, surface number 6indicates the cement layer between the third lens element L3 and thefourth lens element L4. Further, the third lens element L3 has anaspheric object side surface.

Moreover, in the zoom lens system according to Embodiment 14, the thirdlens unit G3 comprises solely a positive meniscus sixth lens element L6with the convex surface facing the image side. The sixth lens element L6has two aspheric surfaces.

In the zoom lens system according to Embodiment 14, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 43, in the zoom lens system according to Embodiment 15,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has an aspheric image side surface, while the secondlens element L2 has an aspheric object side surface.

Further, in the zoom lens system according to Embodiment 15, the secondlens unit G2, in order from the object side to the image side,comprises: a bi-convex third lens element L3; a bi-convex fourth lenselement L4; and a bi-concave fifth lens element L5. Among these, thefourth lens element L4 and the fifth lens element L5 are cemented witheach other. In the surface data in the corresponding numerical exampledescribed later, surface number 8 indicates the cement layer between thefourth lens element L4 and the fifth lens element L5. Further, the thirdlens element L3 has an aspheric object side surface.

Moreover, in the zoom lens system according to Embodiment 15, the thirdlens unit G3 comprises solely a positive meniscus sixth lens element L6with the convex surface facing the image side. The sixth lens element L6has two aspheric surfaces.

In the zoom lens system according to Embodiment 15, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 46, in the zoom lens system according to Embodiment 16,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has an aspheric image side surface, while the secondlens element L2 has an aspheric object side surface.

Further, in the zoom lens system according to Embodiment 16, the secondlens unit G2, in order from the object side to the image side,comprises: a bi-convex third lens element L3; a bi-convex fourth lenselement L4; and a bi-concave fifth lens element L5. Among these, thefourth lens element L4 and the fifth lens element L5 are cemented witheach other. In the surface data in the corresponding numerical exampledescribed later, surface number 8 indicates the cement layer between thefourth lens element L4 and the fifth lens element L5. Further, the thirdlens element L3 has an aspheric object side surface.

Moreover, in the zoom lens system according to Embodiment 16, the thirdlens unit G3 comprises solely a positive meniscus sixth lens element L6with the convex surface facing the image side. The sixth lens element L6has two aspheric surfaces.

In the zoom lens system according to Embodiment 16, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 49, in the zoom lens system according to Embodiment 17,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has an aspheric image side surface, while the secondlens element L2 has an aspheric object side surface.

Further, in the zoom lens system according to Embodiment 17, the secondlens unit G2, in order from the object side to the image side,comprises: a bi-convex third lens element L3; a bi-convex fourth lenselement L4; and a bi-concave fifth lens element L5. Among these, thefourth lens element L4 and the fifth lens element L5 are cemented witheach other. In the surface data in the corresponding numerical exampledescribed later, surface number 8 indicates the cement layer between thefourth lens element L4 and the fifth lens element L5. Further, the thirdlens element L3 has an aspheric object side surface.

Moreover, in the zoom lens system according to Embodiment 17, the thirdlens unit G3 comprises solely a positive meniscus sixth lens element L6with the convex surface facing the image side. The sixth lens element L6has two aspheric surfaces.

In the zoom lens system according to Embodiment 17, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 52, in the zoom lens system according to Embodiment 18,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has an aspheric image side surface, while the secondlens element L2 has an aspheric object side surface.

Further, in the zoom lens system according to Embodiment 18, the secondlens unit G2, in order from the object side to the image side,comprises: a bi-convex third lens element L3; a bi-concave fourth lenselement L4; and a bi-convex fifth lens element L5. Among these, thethird lens element L3 and the fourth lens element L4 are cemented witheach other. Further, the third lens element L3 has an aspheric objectside surface.

Moreover, in the zoom lens system according to Embodiment 18, the thirdlens unit G3 comprises solely a positive meniscus sixth lens element L6with the convex surface facing the image side. The sixth lens element L6has two aspheric surfaces.

In the zoom lens system according to Embodiment 18, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 55, in the zoom lens system according to Embodiment 19,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has an aspheric image side surface, while the secondlens element L2 has an aspheric object side surface.

Further, in the zoom lens system according to Embodiment 19, the secondlens unit G2, in order from the object side to the image side,comprises: a bi-convex third lens element L3; a bi-concave fourth lenselement L4; and a bi-convex fifth lens element L5. Among these, thethird lens element L3 and the fourth lens element L4 are cemented witheach other. Further, the third lens element L3 has an aspheric objectside surface.

Further, in the zoom lens system of Embodiment 19, the third lens unitG3 comprises solely a bi-convex sixth lens element L6. The sixth lenselement L6 has two aspheric surfaces.

In the zoom lens system according to Embodiment 19, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 58, in the zoom lens system according to Embodiment 20,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has an aspheric image side surface, while the secondlens element L2 has an aspheric object side surface.

Further, in the zoom lens system according to Embodiment 20, the secondlens unit G2, in order from the object side to the image side,comprises: a bi-convex third lens element L3; a bi-concave fourth lenselement L4; and a bi-convex fifth lens element L5. Among these, thethird lens element L3 and the fourth lens element L4 are cemented witheach other. Further, the third lens element L3 has an aspheric objectside surface.

Further, in the zoom lens system of Embodiment 20, the third lens unitG3 comprises solely a bi-convex sixth lens element L6. The sixth lenselement L6 has two aspheric surfaces.

In the zoom lens system according to Embodiment 20, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 61, in the zoom lens system according to Embodiment 21,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has two aspheric surfaces.

In the zoom lens system according to Embodiment 21, the second lens unitG2, in order from the object side to the image side, comprises: apositive meniscus third lens element L3 with the convex surface facingthe object side; a negative meniscus fourth lens element L4 with theconvex surface facing the object side; a negative meniscus fifth lenselement L5 with the convex surface facing the object side; and abi-convex sixth lens element L6. Among these, the third lens element L3and the fourth lens element L4 are cemented with each other, while thefifth lens element L5 and the sixth lens element L6 are cemented witheach other. Further, the third lens element L3 has an aspheric objectside surface.

Further, in the zoom lens system of Embodiment 21, the third lens unitG3 comprises solely a bi-convex seventh lens element L7.

In the zoom lens system according to Embodiment 21, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 64, in the zoom lens system according to Embodiment 22,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has two aspheric surfaces.

In the zoom lens system according to Embodiment 22, the second lens unitG2, in order from the object side to the image side, comprises: apositive meniscus third lens element L3 with the convex surface facingthe object side; a negative meniscus fourth lens element L4 with theconvex surface facing the object side; a negative meniscus fifth lenselement L5 with the convex surface facing the object side; and abi-convex sixth lens element L6. Among these, the third lens element L3and the fourth lens element L4 are cemented with each other, while thefifth lens element L5 and the sixth lens element L6 are cemented witheach other. Further, the third lens element L3 has an aspheric objectside surface.

Further, in the zoom lens system of Embodiment 22, the third lens unitG3 comprises solely a bi-convex seventh lens element L7.

In the zoom lens system according to Embodiment 22, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 67, in the zoom lens system according to Embodiment 23,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has two aspheric surfaces.

In the zoom lens system according to Embodiment 23, the second lens unitG2, in order from the object side to the image side, comprises: apositive meniscus third lens element L3 with the convex surface facingthe object side; a negative meniscus fourth lens element L4 with theconvex surface facing the object side; a negative meniscus fifth lenselement L5 with the convex surface facing the object side; and abi-convex sixth lens element L6. Among these, the third lens element L3and the fourth lens element L4 are cemented with each other, while thefifth lens element L5 and the sixth lens element L6 are cemented witheach other. Further, the third lens element L3 has an aspheric objectside surface.

Further, in the zoom lens system of Embodiment 23, the third lens unitG3 comprises solely a bi-convex seventh lens element L7.

In the zoom lens system according to Embodiment 23, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 70, in the zoom lens system according to Embodiment 24,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has two aspheric surfaces.

In the zoom lens system according to Embodiment 24, the second lens unitG2, in order from the object side to the image side, comprises: apositive meniscus third lens element L3 with the convex surface facingthe object side; a negative meniscus fourth lens element L4 with theconvex surface facing the object side; a negative meniscus fifth lenselement L5 with the convex surface facing the object side; and abi-convex sixth lens element L6. Among these, the third lens element L3and the fourth lens element L4 are cemented with each other, while thefifth lens element L5 and the sixth lens element L6 are cemented witheach other. Further, the third lens element L3 has an aspheric objectside surface.

Moreover, in the zoom lens system according to Embodiment 24, the thirdlens unit G3 comprises solely a positive meniscus seventh lens elementL7 with the convex surface facing the image side.

In the zoom lens system according to Embodiment 24, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

As shown in FIG. 73, in the zoom lens system according to Embodiment 25,the first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; and a positive meniscus second lenselement L2 with the convex surface facing the object side. The firstlens element L1 has two aspheric surfaces.

In the zoom lens system according to Embodiment 25, the second lens unitG2, in order from the object side to the image side, comprises: apositive meniscus third lens element L3 with the convex surface facingthe object side; a negative meniscus fourth lens element L4 with theconvex surface facing the object side; a negative meniscus fifth lenselement L5 with the convex surface facing the object side; and abi-convex sixth lens element L6. Among these, the third lens element L3and the fourth lens element L4 are cemented with each other, while thefifth lens element L5 and the sixth lens element L6 are cemented witheach other. Further, the third lens element L3 has an aspheric objectside surface.

Moreover, in the zoom lens system according to Embodiment 25, the thirdlens unit G3 comprises solely a positive meniscus seventh lens elementL7 with the convex surface facing the image side.

In the zoom lens system according to Embodiment 25, in zooming from awide-angle limit to a telephoto limit during image taking, the firstlens unit G1 moves to the object side with locus of a convex to theimage side. Further, the second lens unit G2 moves to the object sidetogether with the aperture diaphragm A, while the third lens unit G3moves to the image side. That is, in zooming from a wide-angle limit toa telephoto limit during image taking, the individual lens units aremoved along the optical axis such that the interval between the firstlens unit G1 and the second lens unit G2 should decrease and that theinterval between the second lens unit G2 and the third lens unit G3should increase.

In particular, in the zoom lens systems according to Embodiments 1 to25, the first lens unit G1, in order from the object side to the imageside, comprises: a lens element having negative optical power; and ameniscus lens element having positive optical power with the convexsurface facing the object side. By virtue of this, a reduced overalloptical length can be realized in a state that various kinds ofaberration, especially, distortion at a wide-angle limit, arecompensated satisfactorily.

In the zoom lens system according to Embodiments 1 to 25, the first lensunit G1 includes at least one lens element having an aspheric surface,or alternatively includes at least two aspheric surfaces. By virtue ofthis, aberration is compensated more successfully.

In the zoom lens system according to Embodiments 1 to 25, the third lensunit G3 is composed of one lens element. Accordingly, the total numberof lens elements is reduced, and so is the overall optical length in thelens system. Further, according to embodiments where the one lenselement constituting the third lens unit G3 includes an asphericsurface, aberration is compensated more successfully.

In the zoom lens system according to Embodiments 1 to 25, the secondlens unit G2 is constructed from three or four lens elements thatinclude one or two sets of cemented lens elements. By virtue of this,the second lens unit G2 has a reduced thickness, and a reduced overalloptical length is realized in the lens system.

Further, in the zoom lens system according to Embodiments 1 to 25, inzooming from a wide-angle limit to a telephoto limit during imagetaking, the first lens unit G1, the second lens unit G2 and the thirdlens unit G3 are moved individually along the optical axis so thatmagnification change is achieved. Here, among these lens units, forexample, the second lens unit G2 is moved in a direction perpendicularto the optical axis, so that image blur caused by hand blurring,vibration and the like can be compensated optically.

When the image blur is to be compensated optically, the second lens unitG2 is moved in a direction perpendicular to the optical axis asdescribed above, so that image blur is compensated in a state that sizeincrease in the entire zoom lens system is suppressed and a compactconstruction is realized and that excellent imaging characteristics suchas small decentering coma aberration and small decentering astigmatismare satisfied.

Conditions are described below that are preferable to be satisfied by azoom lens system like the zoom lens system according to Embodiments 1 to25 which has the above-mentioned basic configuration and in which on theimage side relative to the second lens unit, an aperture diaphragm A isarranged that moves along the optical axis integrally with the secondlens unit in zooming from a wide-angle limit to a telephoto limit duringimage taking. Here, a plurality of preferable conditions are set forthfor the zoom lens system according to each embodiment. A constructionthat satisfies all the plural conditions is most desirable for the zoomlens system. However, when an individual condition is satisfied, a zoomlens system having the corresponding effect can be obtained.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(1) is satisfied.

0.10<D ₂/(I _(r) ×Z ²)<0.30  (1)

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

D₂ is an amount of movement of the second lens unit in a direction froma telephoto limit to a wide-angle limit (defined as positive for themotion from the image side to the object side),

I_(r) is a maximum image height (I_(r)=f_(T)×tan(ω_(T))),

f_(T) is a focal length of the entire system at a telephoto limit,

f_(W) is a focal length of the entire system at a wide-angle limit,

ω_(W) is a half value (°) of a maximum view angle at a wide-angle limit,and

ω_(T) is a half value (°) of a maximum view angle at a telephoto limit.

The condition (1) relates to the amount of movement of the second lensunit. When the value exceeds the upper limit of the condition (1), theamount of movement of the second lens unit necessary in association withzooming increases. This can cause difficulty in compensating aberrationfluctuation during zooming. In contrast, when the value goes below thelower limit of the condition (1), difficulty can arise in simultaneouslycompensating distortion and curvature of field especially at awide-angle limit.

Here, when at least one of the following conditions (1)′ and (1)″ issatisfied, the above-mentioned effect is achieved more successfully.

0.15<D ₂/(I _(r) ×Z ²)  (1)′

D ₂/(I _(r) ×Z ²)<0.25  (1)″

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

Further, it is more preferable that the conditions (1), (1)′ and (1)″are satisfied with a condition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25 in which the second lens unit moves in adirection perpendicular to the optical axis, it is preferable that theentire system satisfies the following conditions (2) and (3).

Y_(T)>Y  (2)

0.05<(Y/Y _(T))/(f/f _(T))<0.60  (3)

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

f is a focal length of the entire system,

f_(T) is a focal length of the entire system at a telephoto limit,

Y is an amount of movement in a direction perpendicular to the opticalaxis at the time of maximum blur compensation in the second lens unitwith a focal length f of the entire system,

Y_(T) is an amount of movement in a direction perpendicular to theoptical axis at the time of maximum blur compensation in the second lensunit with a focal length f_(T) of the entire system at a telephotolimit,

f_(W) is a focal length of the entire system at a wide-angle limit, and

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit.

The conditions (2) and (3) relate to the amount of movement at the timeof maximum blur compensation in the second lens unit that moves in adirection perpendicular to the optical axis. In the case of a zoom lenssystem, when the compensation angle is constant over the entire zoomrange, a larger zoom ratio requires a larger amount of movement of thelens unit or the lens element that moves in a direction perpendicular tothe optical axis. On the contrary, a smaller zoom ratio requires merelya smaller amount of movement of the lens unit or the lens element thatmoves in a direction perpendicular to the optical axis. When thecondition (2) is not satisfied, alternatively when the value exceeds theupper limit of the condition (3), blur compensation becomes excessive.This causes a possibility of enhanced degradation in the opticalperformance. In contrast, when the value goes below the lower limit ofthe condition (3), a possibility of insufficient blur compensationarises.

Here, when at least one of the following conditions (3)′ and (3)″ issatisfied, the above-mentioned effect is achieved more successfully.

0.08<(Y/Y _(T))/(f/f _(T))  (3)′

(Y/Y _(T))/(f/f _(T))<0.50  (3)″

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

Further, it is more preferable that the conditions (3), (3)′ and (3)″are satisfied with a condition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(4) is satisfied.

0.10<(D _(2T) −D _(2W))/(I _(r) ×Z ²)<0.30  (4)

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

D_(2T) is an axial interval from the most image side of the second lensunit to the most object side of the third lens unit at a telephotolimit,

D_(2W) is an axial interval from the most image side of the second lensunit to the most object side of the third lens unit at a wide-anglelimit,

I_(r) is a maximum image height (I_(r)=f_(T)×tan(ω_(T))),

f_(T) is a focal length of the entire system at a telephoto limit,

f_(W) is a focal length of the entire system at a wide-angle limit,

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit, and

ω_(T) is a half value (°) of a maximum view angle at a telephoto limit.

The condition (4) relates to the amount of movement of the second lensunit. When the value exceeds the upper limit of the condition (4), theamount of movement of the second lens unit necessary in association withzooming increases. This can cause difficulty in compensating aberrationfluctuation during zooming. In contrast, when the value goes below thelower limit of the condition (4), difficulty can arise in simultaneouslycompensating distortion and curvature of field especially at awide-angle limit.

Here, when at least one of the following conditions (4)′ and (4)″ issatisfied, the above-mentioned effect is achieved more successfully.

0.15<(D _(2T) −D _(2W))/(I _(r) ×Z ²)  (4)′

(D _(2T) −D _(2W))/(I _(r) ×Z ²)<0.27  (4)″

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

Further, it is more preferable that the conditions (4), (4)′ and (4)″are satisfied with a condition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(5) is satisfied.

−1.60<f _(G1) /f _(G2)<−0.90  (5)

where,

f_(G1) is a focal length of the first lens unit, and

f_(G2) is a focal length of the second lens unit.

The condition (5) sets forth the ratio of the focal lengths of the firstlens unit and the second lens unit. When the value exceeds the upperlimit of the condition (5), the focal length of the second lens unitbecomes excessively small relatively. This can cause difficulty incompensating aberration generated in the second lens unit. In contrast,when the value goes below the lower limit of the condition (5), thefocal length of the first lens unit becomes excessively smallrelatively. This causes difficulty in maintaining the variablemagnification function of the second lens unit, and hence can causedifficulty in constructing a zoom lens system having a zoom ratioexceeding 4 in a state that satisfactory optical performance isobtained.

Here, when at least one of the following conditions (5)′ and (5)″ issatisfied, the above-mentioned effect is achieved more successfully.

−1.50<f _(G1) /f _(G2)  (5)′

f _(G1) /f _(G2)<−1.00  (5)″

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(6) is satisfied.

−0.80<f _(G1) /f _(G3)<0.20  (6)

where,

f_(G1) is a focal length of the first lens unit, and

f_(G3) is a focal length of the third lens unit.

The condition (6) sets forth the ratio of the focal lengths of the firstlens unit and the third lens unit. When the value exceeds the upperlimit of the condition (6), the focal length of the first lens unitbecomes excessively large relatively. This can cause difficulty inachieving a compact zoom lens system. In contrast, when the value goesbelow the lower limit of the condition (6), the focal length of thethird lens unit becomes excessively large relatively. This can causedifficulty in ensuring satisfactory illuminance on the image surface.

Here, when at least one of the following conditions (6)′ and (6)″ issatisfied, the above-mentioned effect is achieved more successfully.

−0.70<f _(G1) /f _(G3)  (6)′

f _(G1) /f _(G3)<−0.50  (6)″

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(7) is satisfied.

0.20<f _(G2) /f _(G3)<0.80  (7)

where,

f_(G2) is a focal length of the second lens unit, and

f_(G3) is a focal length of the third lens unit.

The condition (7) sets forth the ratio of the focal lengths of thesecond lens unit and the third lens unit. When the value exceeds theupper limit of the condition (7), the focal length of the second lensunit becomes excessively large relatively. This can cause difficulty incompensating aberration fluctuation generated in the second lens unit inassociation with zooming. In contrast, when the value goes below thelower limit of the condition (7), the focal length of the third lensunit becomes excessively large relatively. This can cause difficulty inensuring satisfactory illuminance on the image surface.

Here, when at least one of the following conditions (7)′ and (7)″ issatisfied, the above-mentioned effect is achieved more successfully.

0.30<f _(G2) /f _(G3)  (7)′

f _(G2) /f _(G3)<0.50  (7)″

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(8) is satisfied.

−0.80<f _(G1) /f _(T)<−0.30  (8)

(here, f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

f_(G1) is a focal length of the first lens unit,

f_(T) is a focal length of the entire system at a telephoto limit,

f_(W) is a focal length of the entire system at a wide-angle limit, and

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit.

The condition (8) substantially sets forth the focal length of the firstlens unit. When the value exceeds the upper limit of the condition (8),the focal length of the first lens unit becomes excessively large, andhence the amount of movement of the first lens unit increases. Thiscauses difficulty in achieving a compact zoom lens system. In contrast,when the value goes below the lower limit of the condition (8), thefocal length of the first lens unit becomes excessively small, and hencedifficulty arises in maintaining a sufficient air space for ensuring themovement of the second lens unit during zooming. This can causedifficulty in achieving a zoom lens system having a variablemagnification ratio of 4 or greater.

Here, when at least one of the following conditions (8)′ and (8)″ issatisfied, the above-mentioned effect is achieved more successfully.

−0.60<f _(G1) /f _(T)  (8)′

f _(G1) /f _(T)<−0.40  (8)″

(here, f_(T)/f_(W)>4.0 and ω_(W)>35)

Further, it is more preferable that the conditions (8), (8)′ and (8)″are satisfied with a condition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(9) is satisfied.

0.20<f _(G2) /f _(T)<0.80  (9)

(here, f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

f_(G2) is a focal length of the second lens unit,

f_(T) is a focal length of the entire system at a telephoto limit,

f_(W) is a focal length of the entire system at a wide-angle limit, and

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit.

The condition (9) substantially sets forth the focal length of thesecond lens unit. When the value exceeds the upper limit of thecondition (9), the focal length of the second lens unit becomesexcessively large, and hence the amount of movement of the second lensunit during zooming increases. This can cause difficulty in achieving acompact zoom lens system having a variable magnification ratio of 4 orgreater. In contrast, when the value goes below the lower limit of thecondition (9), the focal length of the second lens unit becomesexcessively small. This can cause difficulty in compensating aberrationfluctuation generated in association with the movement of the secondlens unit. Further, when the value goes below the lower limit of thecondition (9), difficulty can arise also in compensating distortion.

Here, when at least one of the following conditions (9)′ and (9)″ issatisfied, the above-mentioned effect is achieved more successfully.

0.30<f _(G2) /f _(T)  (9)′

f _(G2) /f _(T)<0.50  (9)″

(here, f_(T)/f_(W)>4.0 and ω_(W)>35)

Further, it is more preferable that the conditions (9), (9)′ and (9)″are satisfied with a condition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(10) is satisfied.

0.60<f _(G3) /f _(T)<1.50  (10)

(here, f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

f_(G3) is a focal length of the third lens unit,

f_(T) is a focal length of the entire system at a telephoto limit,

f_(W) is a focal length of the entire system at a wide-angle limit, and

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit.

The condition (10) substantially sets forth the focal length of thethird lens unit. When the value exceeds the upper limit of the condition(10), the focal length of the third lens unit becomes excessively large.This can cause difficulty in ensuring appropriate illuminance on theimage surface. In contrast, when the value goes below the lower limit ofthe condition (10), the focal length of the third lens unit becomesexcessively small. This can cause that aberration generated in the thirdlens unit becomes difficult to be compensated by the second lens unit.

Here, when at least one of the following conditions (10)′ and (10)″ issatisfied, the above-mentioned effect is achieved more successfully.

0.70<f _(G3) /f _(T)  (9)′

f _(G3) /f _(T)<1.30  (9)″

(here, f_(T)/f_(W)>4.0 and ω_(W)>35)

Further, it is more preferable that the conditions (10), (10)′ and (10)″are satisfied with a condition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(11) is satisfied.

0.35<(D _(1W) +D _(2W))/(D _(1T) +D _(2T))<1.20  (11)

(here, f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

D_(1W) is an axial interval from the most image side of the first lensunit to the most object side of the second lens unit at a wide-anglelimit,

D_(2W) is an axial interval from the most image side of the second lensunit to the most object side of the third lens unit at a wide-anglelimit,

D_(1T) is an axial interval from the most image side of the first lensunit to the most object side of the second lens unit at a telephotolimit,

D_(2T) is an axial interval from the most image side of the second lensunit to the most object side of the third lens unit at a telephotolimit,

f_(T) is a focal length of the entire system at a telephoto limit,

f_(T) is a focal length of the entire system at a wide-angle limit, and

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit.

The condition (11) relates to the amount of movement of the first lensunit and the second lens unit during zooming. When the value exceeds theupper limit of the condition (11), compensation becomes insufficient fordistortion at a wide-angle limit, and hence difficulty can arise inachieving satisfactory optical performance. In contrast, when the valuegoes below the lower limit of the condition (11), the amount of movementof the individual lens units necessary in association with zoomingincreases. This can cause difficulty in compensating aberrationfluctuation during zooming.

Here, when at least one of the following conditions (11)′ and (11)″ issatisfied, the above-mentioned effect is achieved more successfully.

0.45<(D _(1W) +D _(2W))/(D _(1T) +D _(2T))  (11)′

(D _(1W) +D _(2W))/(D _(1T) +D _(2T))<0.80  (11)″

(here, f_(T)/f_(W)>4.0 and (ω_(W)>35)

Further, it is more preferable that the conditions (11), (11)′ and (11)″are satisfied with a condition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(12) is satisfied.

2.00<(D _(2T) −D _(2W))/f _(W)<6.00  (12)

(here, f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

D_(2T) is an axial interval from the most image side of the second lensunit to the most object side of the third lens unit at a telephotolimit,

D_(2W) is an axial interval from the most image side of the second lensunit to the most object side of the third lens unit at a wide-anglelimit,

f_(T) is a focal length of the entire system at a telephoto limit,

f_(W) is a focal length of the entire system at a wide-angle limit, and

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit.

The condition (12) relates to the amount of movement of the second lensunit. When the value exceeds the upper limit of the condition (12), theamount of movement of the second lens unit necessary in association withzooming increases. This can cause difficulty in compensating aberrationfluctuation during zooming. In contrast, when the value goes below thelower limit of the condition (12), a tendency becomes dominant that thefocal length of the second lens unit becomes small. This can causedifficulty in compensating distortion especially at a wide-angle limit.

Here, when at least one of the following conditions (12)′ and (12)″ issatisfied, the above-mentioned effect is achieved more successfully.

3.00<(D _(2T) −D _(2W))/f _(W)  (12)′

(D _(2T) −D _(2W))/f _(W)<5.50  (12)″

(here, f_(T)/f_(W)>4.0 and ω_(W)>35)

Further, it is more preferable that the conditions (12), (12)′ and (12)″are satisfied with a condition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(13) is satisfied.

0.65<(D _(2T) −D _(2W))/f _(T)<1.10  (13)

(here, f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

D_(2T) is an axial interval from the most image side of the second lensunit to the most object side of the third lens unit at a telephotolimit,

D_(2W) is an axial interval from the most image side of the second lensunit to the most object side of the third lens unit at a wide-anglelimit,

f_(T) is a focal length of the entire system at a telephoto limit,

f_(W) is a focal length of the entire system at a wide-angle limit, and

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit.

The condition (13) relates to the amount of movement of the second lensunit. When the value exceeds the upper limit of the condition (13), theamount of movement of the second lens unit necessary in association withzooming increases. This can cause difficulty in compensating aberrationfluctuation during zooming. In contrast, when the value goes below thelower limit of the condition (13), a tendency becomes dominant that thefocal length of the second lens unit becomes small. This can causedifficulty in simultaneously compensating distortion and curvature offield especially at a wide-angle limit.

Here, when at least one of the following conditions (13)′ and (13)″ issatisfied, the above-mentioned effect is achieved more successfully.

0.75<(D _(2T) −D _(2W))/f _(T)  (13)′

(D _(2T) −D _(2W))/f _(T)<0.95  (13)″

(here, f_(T)/f_(W)>4.0 and ω_(W)>35)

Further, it is more preferable that the conditions (13), (13)′ and (13)″are satisfied with a condition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(14) is satisfied.

0.00<D _(1T) /I _(r)<0.10  (14)

(here, f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

D_(1T) is an axial interval from the most image side of the first lensunit to the most object side of the second lens unit at a telephotolimit,

I_(r) is a maximum image height (I_(r)=f_(T)×tan(ω_(T))),

f_(T) is a focal length of the entire system at a telephoto limit,

f_(W) is a focal length of the entire system at a wide-angle limit,

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit, and

ω_(T) is a half value (°) of a maximum view angle at a telephoto limit.

The condition (14) relates to the air space between the first lens unitand the second lens unit. When the value exceeds the upper limit of thecondition (14), the air space between the first lens unit and the secondlens unit becomes excessively large. This causes difficulty in obtainingsatisfactory magnification in the zoom lens system, and can causedifficulty in compensating distortion especially at a wide-angle limit.In contrast, when the value goes below the lower limit of the condition(14), the air space between the first lens unit and the second lens unitbecomes excessively small. This similarly can cause difficulty incompensating distortion at a wide-angle limit.

Further, it is more preferable that the condition (14) is satisfied witha condition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(15) is satisfied.

0.10<(f _(W) /I _(r))×(f _(W) /f _(T))<0.40  (15)

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

I_(r) is a maximum image height (I_(r)=f_(T)×tan(ω_(T))),

f_(T) is a focal length of the entire system at a telephoto limit,

f_(W) is a focal length of the entire system at a wide-angle limit, and

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit.

The condition (15) relates to the variable magnification ratio of thezoom lens system. When the value falls outside the range of thecondition (15), difficulty can arise in ensuring a zoom ratio of 4 orthe like in a state that a satisfactory view angle at a wide-angle limitis obtained.

Here, when at least one of the following conditions (15)′ and (15)″ issatisfied, the above-mentioned effect is achieved more successfully.

0.20<(f _(W) /I _(r))×(f _(W) /f _(T))  (15)′

(f _(W) /I _(r))×(f _(W) /f _(T))<0.35  (15)″

(here, f_(T)/f_(W)>4.0 and ω_(W)>35)

Further, it is more preferable that the conditions (15), (15)′ and (15)″are satisfied with a condition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(16) is satisfied.

2.50<tan(ω_(W))×Z<6.00  (16)

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

f_(T) is a focal length of the entire system at a telephoto limit,

f_(W) is a focal length of the entire system at a wide-angle limit, and

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit.

The condition (16) relates to the variable magnification ratio of thezoom lens system. When the value falls outside the range of thecondition (16), difficulty can arise in ensuring a zoom ratio of 4 orthe like in a state that a satisfactory view angle at a wide-angle limitis obtained.

Here, when at least one of the following conditions (16)′ and (16)″ issatisfied, the above-mentioned effect is achieved more successfully.

3.00<tan(ω_(W))×Z  (16)′

tan(ω_(W))×Z<5.50  (16)″

(here, f_(T)/f_(W)>4.0 and ω_(W)>35)

Further, it is more preferable that the conditions (16), (16)′ and (16)″are satisfied with a condition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(17) is satisfied.

2.00<|f _(W) ×f _(G1) |/I _(r) ²<6.00  (17)

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

I_(r) is a maximum image height (I_(r)=f_(T)×tan(ω_(T))),

f_(G1) is a focal length of the first lens unit,

f_(T) is a focal length of the entire system at a telephoto limit,

f_(W) is a focal length of the entire system at a wide-angle limit,

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit, and

ω_(T) is a half value (°) of a maximum view angle at a telephoto limit.

The condition (17) substantially sets forth the focal length of thefirst lens unit. When the value exceeds the upper limit of the condition(17), the focal length of the first lens unit becomes excessively large,and hence the amount of movement of the first lens unit during zoomingincreases. This can cause difficulty in achieving a compact zoom lenssystem having a variable magnification ratio of 4 or greater. Incontrast, when the value goes below the lower limit of the condition(17), the focal length of the first lens unit becomes excessively small.This can cause difficulty in compensating distortion in a state that awide view angle is obtained at a wide-angle limit.

Here, when at least one of the following conditions (17)′ and (17)″ issatisfied, the above-mentioned effect is achieved more successfully.

2.50<|f _(W) ×f _(G1) |/I _(r) ²  (17)′

|f_(W) ×f _(G1) |/I _(r) ²<5.00  (17)″

(here, f_(T)/f_(W)>4.0 and ω_(W)>35)

Further, it is more preferable that the conditions (17), (17)′ and (17)″are satisfied with a condition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(18) is satisfied.

2.00<(f _(W) ·f _(G2))/I _(r) ²<6.00  (18)

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

I_(r) is a maximum image height (I_(r)=f_(T)×tan(ω_(T))),

f_(G2) is a focal length of the second lens unit,

f_(T) is a focal length of the entire system at a telephoto limit,

f_(W) is a focal length of the entire system at a wide-angle limit,

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit, and

ω_(T) is a half value (°) of a maximum view angle at a telephoto limit.

The condition (18) substantially sets forth the focal length of thesecond lens unit. When the value exceeds the upper limit of thecondition (18), the focal length of the second lens unit becomesexcessively large, and hence the amount of movement of the second lensunit during zooming increases. This can cause difficulty in achieving acompact zoom lens system having a variable magnification ratio of 4 orgreater. In contrast, when the value goes below the lower limit of thecondition (18), the focal length of the second lens unit becomesexcessively small. This can cause difficulty in compensating aberrationfluctuation generated in association with the movement of the secondlens unit. Further, when the value goes below the lower limit of thecondition (18), difficulty can arise also in compensating distortion.

Here, when at least one of the following conditions (18)′ and (18)″ issatisfied, the above-mentioned effect is achieved more successfully.

2.50<(f _(W) ·f _(G2))/I _(r) ²  (18)′

(f _(W) ·f _(G2))/I _(r) ²<5.00  (18)

(here, f_(T)/f_(W)>4.0 and ω_(W)>35)

Further, it is more preferable that the conditions (18), (18)′ and (18)″are satisfied with a condition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(19) is satisfied.

(D _(G1) +D _(G2) +D _(G3))/f _(T)<0.70  (19)

(here, f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

D_(G1) is an axial interval from the most object side to the most imageside of the first lens unit,

D_(G2) is an axial interval from the most object side to the most imageside of the second lens unit,

D_(G3) is an axial interval from the most object side to the most imageside of the third lens unit,

f_(T) is a focal length of the entire system at a telephoto limit,

f_(W) is a focal length of the entire system at a wide-angle limit, and

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit.

The condition (19) relates to the overall length at the time ofaccommodation. When a so-called retraction construction that is freefrom protrusions at the time of accommodation is to be realized, thetotal of the axial intervals between the individual lens units need besufficiently small. When the value exceeds the upper limit of thecondition (19), the overall length at the time of retraction becomesexcessively large, and hence this situation is unpreferable.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(20) is satisfied.

3.5<(F _(W) ×F _(T))/Z<5.0  (20)

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

F_(W) is a minimum F-number at a wide-angle limit,

F_(T) is a minimum F-number at a telephoto limit,

f_(T) is a focal length of the entire system at a telephoto limit,

f_(W) is a focal length of the entire system at a wide-angle limit, and

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit.

The condition (20) relates to the F-number of the zoom lens system. Whenthe value falls outside the range of the condition (20), difficulty canarise in achieving a bright zoom lens system having a small F-number ina state that satisfactory optical performance is obtained.

When the following condition (20)′ is satisfied, the above-mentionedeffect is achieved more successfully.

(F _(W) ×F _(T))/Z<4.7  (20)′

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

Further, it is more preferable that the conditions (20) and (20)′ aresatisfied with a condition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(21) is satisfied.

1.5<L _(T)/(I _(r) ×Z)<2.6  (21)

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

I_(r) is a maximum image height (I_(r)=f_(T)×tan(ω_(T))),

L_(T) is an overall length at a telephoto limit (a distance from themost object side of the first lens unit to the image surface),

f_(T) is a focal length of the entire system at a telephoto limit,

f_(W) is a focal length of the entire system at a wide-angle limit,

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit, and

ω_(T) is a half value (°) of a maximum view angle at a telephoto limit.

The condition (21) sets forth the overall length especially at atelephoto limit. When the value exceeds the upper limit of the condition(21), a tendency of increase in the overall length of the zoom lenssystem becomes dominant. This can cause difficulty in achieving acompact zoom lens system. In contrast, when the value goes below thelower limit of the condition (21), a tendency of decrease in the overalllength of the zoom lens system becomes dominant, and hence the focallength of each lens unit becomes excessively small. This can causedifficulty in compensating various kinds of aberration.

Here, it is more preferable that the condition (21) is satisfied with acondition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(22) is satisfied.

4.0<(D _(G2)+(D _(G2A)))/(D _(G2A))<20.0  (22)

where,

D_(G2) is an axial interval from the most object side to the most imageside of the second lens unit, and

D_(G2A) is an axial interval from the most image side of the second lensunit to the aperture diaphragm.

The condition (22) sets forth an appropriate interval between the secondlens unit and the aperture diaphragm. When the value exceeds the upperlimit of the condition (22), a tendency becomes dominant that thediaphragm position becomes distant from the second lens unit. Thus, theeffective diameter of the first lens unit becomes excessively large, anddifficulty can arise in compensating distortion and coma aberrationespecially at a wide-angle limit. In contrast, when the value goes belowthe lower limit of the condition (22), a tendency becomes dominant thatthe diaphragm position becomes close to the second lens unit. This cancause difficulty in compensation of spherical aberration to be performedby the second lens unit.

When the following condition (22)′ is satisfied, the above-mentionedeffect is achieved more successfully.

8.0<(D _(G2)+(D _(G2A)))/(D _(G2A))  (22)

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, in a case that the first lens unit, in orderfrom the object side to the image side, comprises a first lens elementhaving negative optical power and a second lens element having positiveoptical power, it is preferable that the following condition (23) issatisfied.

−2.00<f _(L2) /f _(G1)<−1.00  (23)

where,

f_(L2) is a focal length of the second lens element, and

f_(G1) is a focal length of the first lens unit.

The condition (23) sets forth the focal length of the second lenselement of the first lens unit. When the value exceeds the upper limitof the condition (23), the focal length of the second lens elementbecomes excessively large. This can cause difficulty in compensatingcoma aberration especially at a telephoto limit. In contrast, when thevalue goes below the lower limit of the condition (23), the focal lengthof the second lens element becomes excessively small. This can causedifficulty in compensating distortion at a wide-angle limit.

When the following condition (23)′ is satisfied, the above-mentionedeffect is achieved more successfully.

−1.60<f _(L2) /f _(G1)  (23)′

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, in a case that the first lens unit, in orderfrom the object side to the image side, comprises a first lens elementhaving negative optical power and a second lens element having positiveoptical power, it is preferable that the following condition (24) issatisfied.

0.20<R _(2F) /f _(T)<0.50  (24)

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

R_(2F) is a radius of curvature of the object side surface of the secondlens element,

f_(T) is a focal length of the entire system at a telephoto limit,

f_(W) is a focal length of the entire system at a wide-angle limit, and

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit.

The condition (24) sets forth the object side surface of the second lenselement of the first lens unit. When the value falls outside the rangeof the condition (24), difficulty can arise in compensating distortionat a wide-angle limit.

When the following condition (24)′ is satisfied, the above-mentionedeffect is achieved more successfully.

R _(2F) /f _(T)<0.45  (24)′

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

Further, it is more preferable that the conditions (24) and (24)′ aresatisfied with a condition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, in a case that the first lens unit, in orderfrom the object side to the image side, comprises a first lens elementhaving negative optical power and a second lens element having positiveoptical power, it is preferable that the following condition (25) issatisfied.

0.30<R _(2R) /f _(T)<0.90  (25)

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

R_(2R) is a radius of curvature of the image side surface of the secondlens element,

f_(T) is a focal length of the entire system at a telephoto limit,

f_(W) is a focal length of the entire system at a wide-angle limit, and

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit.

The condition (25) sets forth the image side surface of the second lenselement of the first lens unit. When the value falls outside the rangeof the condition (25), difficulty can arise in compensating distortionat a wide-angle limit.

Here, when the following condition (25)′ is satisfied, theabove-mentioned effect is achieved more successfully.

R _(2R) /f _(T)<0.85  (25)′

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

Further, it is more preferable that the conditions (25) and (25)′ aresatisfied with a condition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, in a case that the first lens unit, in orderfrom the object side to the image side, comprises a first lens elementhaving negative optical power and a second lens element having positiveoptical power, it is preferable that the following condition (26) issatisfied.

0.50<f _(L2) /f _(T)<1.00  (26)

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

f_(L2) is a focal length of the second lens element,

f_(T) is a focal length of the entire system at a telephoto limit,

f_(W) is a focal length of the entire system at a wide-angle limit, and

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit.

The condition (26) sets forth the focal length of the second lenselement of the first lens unit. When the value exceeds the upper limitof the condition (26), the focal length of the second lens elementbecomes excessively large, and hence the negative optical power of theentire first lens unit becomes small. This can cause difficulty incompensating various kinds of aberration, especially distortion, in astate that the focal length is reduced at a wide-angle limit. Further,when the value exceeds the upper limit of the condition (26),magnification chromatic aberration can be generated remarkably. Incontrast, when the value goes below the lower limit of the condition(26), the focal length of the second lens element becomes excessivelysmall. This can cause difficulty in ensuring a variable magnificationratio as high as 4 or greater in a state that satisfactory opticalperformance is obtained. Further, compensation of distortion can becomeinsufficient.

When the following condition (26)′ is satisfied, the above-mentionedeffect is achieved more successfully.

f _(L2) /f _(T)<0.90  (26)′

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

Further, it is more preferable that the conditions (26) and (26)′ aresatisfied with a condition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, in a case that the second lens unit has apositive lens element on the most object side, it is preferable that thefollowing condition (27) is satisfied.

0.40<f _(L3) /f _(G2)<1.00  (27)

where,

f_(L3) is a focal length of the positive lens element arranged on themost object side of the second lens unit, and

f_(G2) is a focal length of the second lens unit.

The condition (27) sets forth the positive lens element arranged on themost object side of the second lens unit. When the value exceeds theupper limit of the condition (27), difficulty can arise in compensatingdistortion at a wide-angle limit. In contrast, when the value goes belowthe lower limit of the condition (27), difficulty arises in compensatingspherical aberration over the entire zoom range, and hence sizereduction and optical performance cannot simultaneously be achieved.This causes a possibility of degradation in the basic imagingperformance as an optical system.

When the following condition (27)′ is satisfied, the above-mentionedeffect is achieved more successfully.

f _(L3) /f _(G2)≦0.92  (27)′

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 21 to 25, in a case that the second lens unit, in orderfrom the object side to the image side, comprises a first cemented lenselement constructed by cementing two lens elements with each other and asecond cemented lens element constructed by cementing two lens elementswith each other, it is preferable that the following condition (28) issatisfied.

2.00<f _(G2a) /f _(G2b)<3.00  (28)

where,

f_(G2a) is a focal length of the first cemented lens element, and

f_(G2b) is a focal length of the second cemented lens element.

The condition (28) sets forth appropriate focal lengths of cemented lenselements in a case that the second lens unit is composed of two sets ofthe cemented lens elements. When the value exceeds the upper limit ofthe condition (28), decentering error sensitivity of the second lensunit becomes excessively high. Thus, performance degradation can becaused by an assembling error. In particular, degradation in imagesurface property can be caused by relative decentering. In contrast,when the value goes below the lower limit of the condition (28),difficulty can arise in compensating spherical aberration generated inthe second lens unit.

When the following condition (28)′ is satisfied, the above-mentionedeffect is achieved more successfully.

2.25<f _(G2a) /f _(G2b)  (28)′

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25 in which the second lens unit moves in adirection perpendicular to the optical axis, it is preferable that thefollowing condition (29) is satisfied.

2.00<(1−m _(2T))×m _(3T)<5.00  (29)

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

m_(2T) is a lateral magnification of the second lens unit at a telephotolimit in an infinity in-focus condition,

m_(3T) is a lateral magnification of the third lens unit at a telephotolimit in an infinity in-focus condition,

f_(T) is a focal length of the entire system at a telephoto limit,

f_(T) is a focal length of the entire system at a wide-angle limit, and

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit.

The condition (29) is a condition for obtaining satisfactory imagingcharacteristics in a case that image blur compensation is performed bymoving the second lens unit in a direction perpendicular to the opticalaxis. When the value exceeds the upper limit of the condition (29), theamount of movement of the second lens unit required for decentering theimage by a predetermined amount becomes excessively small. Thus,difficulty arises in causing the second lens unit to perform parallelmovement with precision. Accordingly, pixel deviation during imagetaking cannot sufficiently be reduced. This can cause difficulty inachieving satisfactory imaging characteristics in an image blurcompensation state. In contrast, when the value goes below the lowerlimit of the condition (29), the amount of decentering of the secondlens unit required for decentering the image by a predetermined amountbecomes excessively large. Thus, a large aberration change is generatedin association with the parallel movement of the second lens unit. Thiscauses a possibility of degradation in the imaging characteristics inthe image periphery part.

When the following condition (29)′ is satisfied, the above-mentionedeffect is achieved more successfully.

2.50<(1−m _(2T))×m _(3T)  (29)′

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

Further, it is more preferable that the conditions (29) and (29)′ aresatisfied with a condition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(30) is satisfied.

3.50<m _(2T) /m _(2W)<5.50  (30)

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

m_(2T) is a lateral magnification of the second lens unit at a telephotolimit in an infinity in-focus condition,

m_(2W) is a lateral magnification of the second lens unit at awide-angle limit in an infinity in-focus condition,

f_(T) is a focal length of the entire system at a telephoto limit,

f_(W) is a focal length of the entire system at a wide-angle limit, and

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit.

The condition (30) sets forth magnification change in the second lensunit, and substantially optimizes a variable magnification load to thesecond lens unit during zooming. When the value falls outside the rangeof the condition (30), the variable magnification load to the secondlens unit becomes inappropriate. This can cause difficulty inconstructing a compact zoom lens system having satisfactory opticalperformance.

When the following condition (30)′ is satisfied, the above-mentionedeffect is achieved more successfully.

4.00<m _(2T) /m _(2W)  (30)′

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

Further, it is more preferable that the conditions (30) and (30)′ aresatisfied with a condition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25, it is preferable that the following condition(31) is satisfied.

−6.00<(1−m _(2T) /m _(2W))×(m _(3T) /m _(3W))<−3.00  (31)

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

m_(2T) is a lateral magnification of the second lens unit at a telephotolimit in an infinity in-focus condition,

m^(2W) is a lateral magnification of the second lens unit at awide-angle limit in an infinity in-focus condition,

m_(3T) is a lateral magnification of the third lens unit at a telephotolimit in an infinity in-focus condition,

m_(3W) is a lateral magnification of the third lens unit at a wide-anglelimit in an infinity in-focus condition,

f_(T) is a focal length of the entire system at a telephoto limit,

f_(W) is a focal length of the entire system at a wide-angle limit, and

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit.

The condition (31) sets forth magnification change in the second lensunit and the third lens unit, and substantially optimizes a variablemagnification load to the second lens unit and the third lens unitduring zooming. When the value falls outside the range of the condition(31), distribution of the variable magnification load between the secondlens unit and the third lens unit becomes inappropriate. This can causedifficulty in constructing a compact zoom lens system havingsatisfactory optical performance.

When the following condition (31)′ is satisfied, the above-mentionedeffect is achieved more successfully.

−4.00<(1−m _(2T) /m _(2W))×(m _(3T) /m _(3W))  (31)′

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

Further, it is more preferable that the conditions (31) and (31)′ aresatisfied with a condition ω_(W)>40.

For example, in a zoom lens system like the zoom lens system accordingto Embodiments 1 to 25 in which the second lens unit moves in adirection perpendicular to the optical axis, it is preferable that thefollowing condition (32) is satisfied.

1.00<(1−m _(2W))×m _(3W)<1.50  (32)

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

where,

m^(2W) is a lateral magnification of the second lens unit at awide-angle limit in an infinity in-focus condition,

m_(3W) is a lateral magnification of the third lens unit at a wide-anglelimit in an infinity in-focus condition,

f_(T) is a focal length of the entire system at a telephoto limit,

f_(W) is a focal length of the entire system at a wide-angle limit, and

ω_(W) is a half value (°) of the maximum view angle at a wide-anglelimit.

The condition (32) is a condition for obtaining satisfactory imagingcharacteristics in a case that image blur compensation is performed bymoving the second lens unit in a direction perpendicular to the opticalaxis. When the value exceeds the upper limit of the condition (32), theamount of movement of the second lens unit required for decentering theimage by a predetermined amount becomes excessively small. Thus,difficulty can arise in causing the second lens unit to perform parallelmovement with precision. Accordingly, pixel deviation during imagetaking cannot sufficiently be reduced. This can cause difficulty inachieving satisfactory imaging characteristics in an image blurcompensation state. In contrast, when the value goes below the lowerlimit of the condition (32), the amount of decentering of the secondlens unit required for decentering the image by a predetermined amountbecomes excessively large. Thus, a large aberration change is generatedin association with the parallel movement of the second lens unit. Thiscauses a possibility of degradation in the imaging characteristics inthe image periphery part.

When the following condition (32)′ is satisfied, the above-mentionedeffect is achieved more successfully.

1.15<(1−m _(2T))×m _(3T)  (32)′

(here, Z=f_(T)/f_(W)>4.0 and ω_(W)>35)

Further, it is more preferable that the conditions (32) and (32)′ aresatisfied with a condition ω_(W)>40.

The lens units constituting the zoom lens system of Embodiments 1 to 25are composed exclusively of refractive type lens elements that deflectthe incident light by refraction (that is, lens elements of a type inwhich deflection is achieved at the interface between media each havinga distinct refractive index). However, the present invention is notlimited to the zoom lens system of this construction. For example, thelens units may employ diffractive type lens elements that deflect theincident light by diffraction; refractive-diffractive hybrid type lenselements that deflect the incident light by a combination of diffractionand refraction; or gradient index type lens elements that deflect theincident light by distribution of refractive index in the medium.

Moreover, in each embodiment, a configuration has been described that onthe object side relative to the image surface S (that is, between theimage surface S and the most image side lens surface of the third lensunit G3), a plane parallel plate such as an optical low-pass filter anda face plate of an image sensor is provided. This low-pass filter maybe: a birefringent type low-pass filter made of, for example, a crystalwhose predetermined crystal orientation is adjusted; or a phase typelow-pass filter that achieves required characteristics of opticalcut-off frequency by diffraction.

Embodiment 26

FIG. 76 is a schematic construction diagram of a digital still cameraaccording to Embodiment 26. In FIG. 76, the digital still cameracomprises: an imaging device having a zoom lens system 1 and an imagesensor 2 that is a CCD; a liquid crystal display monitor 3; and a body4. The employed zoom lens system 1 is a zoom lens system according toEmbodiment 1. In FIG. 76, the zoom lens system 1 comprises a first lensunit G1, a second lens unit G2, an aperture diaphragm A and a third lensunit G3. In the body 4, the zoom lens system 1 is arranged on the frontside, while the image sensor 2 is arranged on the rear side of the zoomlens system 1. On the rear side of the body 4, the liquid crystaldisplay monitor 3 is arranged, while an optical image of a photographicobject generated by the zoom lens system 1 is formed on an image surfaceS.

The lens barrel comprises a main barrel 5, a moving barrel 6 and acylindrical cam 7. When the cylindrical cam 7 is rotated, the first lensunit G1, the second lens unit G2, the aperture diaphragm A and the thirdlens unit G3 move to predetermined positions relative to the imagesensor 2, so that magnification change can be achieved ranging from awide-angle limit to a telephoto limit. The third lens unit G3 is movablein an optical axis direction by a motor for focus adjustment.

As such, when the zoom lens system according to Embodiment 1 is employedin a digital still camera, a small digital still camera is obtained thathas a high resolution and high capability of compensating the curvatureof field and that has a short overall optical length at the time ofnon-use. Here, in the digital still camera shown in FIG. 76, any one ofthe zoom lens systems according to Embodiments 2 to 25 may be employedin place of the zoom lens system according to Embodiment 1. Further, theoptical system of the digital still camera shown in FIG. 76 isapplicable also to a digital video camera for moving images. In thiscase, moving images with high resolution can be acquired in addition tostill images.

Here, the digital still camera according to the present Embodiment 26has been described for a case that the employed zoom lens system 1 is azoom lens system according to Embodiments 1 to 25. However, in thesezoom lens systems, the entire zooming range need not be used. That is,in accordance with a desired zooming range, a range where satisfactoryoptical performance is obtained may exclusively be used. Then, the zoomlens system may be used as one having a lower magnification than thezoom lens system described in Embodiments 1 to 25.

Further, Embodiment 26 has been described for a case that the zoom lenssystem is applied to a lens barrel of so-called retraction construction.However, the present invention is not limited to this. For example, to alens barrel of so-called bending configuration may be applied the zoomlens system where a prism having an internal reflective surface or afront surface reflective mirror is arranged at an arbitrary positionwithin the first lens unit G1 or the like. Further, in Embodiment 26,the zoom lens system may be applied to a so-called sliding lens barrelwhere a part, such as the entire second lens unit G2, of the lens unitsthat constitute the zoom lens system is retracted from the optical axisat the time of retraction.

Further, an imaging device comprising a zoom lens system according toEmbodiments 1 to 25 described above and an image sensor such as a CCD ora CMOS may be applied to a mobile telephone, a PDA (Personal DigitalAssistance), a surveillance camera in a surveillance system, a Webcamera, a vehicle-mounted camera or the like.

Numerical examples are described below in which the zoom lens systemsaccording to Embodiments 1 to 25 are implemented. In the numericalexamples, the units of the length in the tables are all “mm”, while theunits of the view angle are all “°”. Moreover, in the numericalexamples, r is the radius of curvature, d is the axial distance, nd isthe refractive index to the d-line, and vd is the Abbe number to thed-line. In the numerical examples, the surfaces marked with * areaspheric surfaces, and the aspheric surface configuration is defined bythe following expression.

$z = {\frac{h^{2}/r}{1 + \sqrt{1 - {\left( {1 - \kappa} \right)\left( {h/r} \right)^{2}}}} + {A\; 4h^{4}} + {A\; 6h^{6}} + {A\; 8h^{8}} + {A\; 10h^{10}} + {A\; 12h^{12}} + {A\; 14h^{14}}}$

Here, κ is the conic constant, A4, A6, A8, A10, A12 and A14 are afourth-order, sixth-order, eighth-order, tenth-order, twelfth-order andfourteenth-order aspherical coefficients, respectively.

FIGS. 2, 5, 8, 11, 14, 17, 20, 23, 26, 29, 32, 35, 38, 41, 44, 47, 50,53, 56, 59, 62, 65, 68, 71 and 74 are longitudinal aberration diagramsof the zoom lens systems according to Embodiments 1 to 25, respectively.

In each longitudinal aberration diagram, part (a) shows the aberrationat a wide-angle limit, part (b) shows the aberration at a middleposition, and part (c) shows the aberration at a telephoto limit. Eachlongitudinal aberration diagram, in order from the left-hand side, showsthe spherical aberration (SA (mm)), the astigmatism (AST (mm)) and thedistortion (DIS (%)). In each spherical aberration diagram, the verticalaxis indicates the F-number (in each FIG., indicated as “F”), and thesolid line, the short dash line and the long dash line indicate thecharacteristics to the d-line, the F-line and the C-line, respectively.In each astigmatism diagram, the vertical axis indicates the imageheight (in each FIG., indicated as “H”), and the solid line and the dashline indicate the characteristics to the sagittal plane (in each FIG.,indicated as “s”) and the meridional plane (in each FIG., indicated as“m”), respectively. In each distortion diagram, the vertical axisindicates the image height (in each FIG., indicated as “H”).

FIGS. 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, 48, 51,54, 57, 60, 63, 66, 69, 72 and 75 are lateral aberration diagrams of thezoom lens systems at a telephoto limit according to Embodiments 1 to 25,respectively.

In each lateral aberration diagram, the aberration diagrams in the upperthree parts correspond to a basic state where image blur compensation isnot performed at a telephoto limit, while the aberration diagrams in thelower three parts correspond to an image blur compensation state wherethe entire second lens unit G2 is moved by a predetermined amount in adirection perpendicular to the optical axis at a telephoto limit. Amongthe lateral aberration diagrams of a basic state, the upper part showsthe lateral aberration at an image point of 75% of the maximum imageheight, the middle part shows the lateral aberration at the axial imagepoint, and the lower part shows the lateral aberration at an image pointof −75% of the maximum image height. Among the lateral aberrationdiagrams of an image blur compensation state, the upper part shows thelateral aberration at an image point of 75% of the maximum image height,the middle part shows the lateral aberration at the axial image point,and the lower part shows the lateral aberration at an image point of−75% of the maximum image height. In each lateral aberration diagram,the horizontal axis indicates the distance from the principal ray on thepupil surface, and the solid line, the short dash line and the long dashline indicate the characteristics to the d-line, the F-line and theC-line, respectively. In each lateral aberration diagram, the meridionalplane is adopted as the plane containing the optical axis of the firstlens unit G1 and the optical axis of the second lens unit G2.

In the zoom lens system according to each example, the amount (Y_(T)) ofmovement of the second lens unit G2 in a direction perpendicular to theoptical axis in an image blur compensation state at a telephoto limit isas follows.

Example Amount of movement Y_(T) (mm) 1 0.0820 2 0.0848 3 0.0838 40.0838 5 0.0838 6 0.1025 7 0.0935 8 0.0847 9 0.0860 10 0.1038 11 0.082912 0.0854 13 0.0933 14 0.0841 15 0.1016 16 0.0972 17 0.0966 18 0.0974 190.0940 20 0.0989 21 0.0650 22 0.0707 23 0.0762 24 0.0678 25 0.0775

Here, when the shooting distance is infinity, at a telephoto limit, theamount of image decentering in a case that the zoom lens system inclinesby 0.6° is equal to the amount of image decentering in a case that theentire second lens unit G2 moves in parallel by each of theabove-mentioned values in a direction perpendicular to the optical axis.

As seen from the lateral aberration diagrams, satisfactory symmetry isobtained in the lateral aberration at the axial image point. Further,when the lateral aberration at the +75% image point and the lateralaberration at the −75% image point are compared with each other in abasic state, all have a small degree of curvature and almost the sameinclination in the aberration curve. Thus, decentering coma aberrationand decentering astigmatism are small. This indicates that sufficientimaging performance is obtained even in an image blur compensationstate. Further, when the image blur compensation angle of a zoom lenssystem is the same, the amount of parallel movement required for imageblur compensation decreases with decreasing focal length of the entirezoom lens system. Thus, at arbitrary zoom positions, sufficient imageblur compensation can be performed for image blur compensation angles upto 0.6° without degrading the imaging characteristics.

Numerical Example 1

The zoom lens system of Numerical Example 1 corresponds to Embodiment 1shown in FIG. 1. Table 1 shows the surface data of the zoom lens systemof Numerical Example 1. Table 2 shows the aspherical data. Table 3 showsvarious data.

TABLE 1 (Surface data) Surface number r d nd vd Object surface ∞  1*188.92300 1.06000 1.85976 40.6  2* 5.44500 1.73200  3* 9.22600 1.980001.99537 20.7  4 17.36000 Variable  5* 4.94900 1.55900 1.80434 40.8  6117.92500 0.15300  7 13.15200 1.05000 1.72916 54.7  8 −21.47500 0.010001.56732 42.8  9 −21.47500 0.40000 1.76182 26.6 10 3.74800 0.58300 1122.33900 1.01500 1.69680 55.5 12 −19.41000 0.40000 13 (Diaphragm) ∞Variable 14* −116.08400 1.40700 1.68863 52.8 15* −12.09600 Variable 16 ∞0.28000 1.51680 64.2 17 ∞ 0.50000 18 ∞ 0.50000 1.51680 64.2 19 ∞ (BF)Image surface ∞

TABLE 2 (Aspherical data) Surface No. 1 K = 0.00000E+00, A4 =−1.00660E−06, A6 = 1.42786E−06, A8 = −2.21841E−08, A10 = 4.62309E−11,A12 = 0.00000E+00, A14 = 0.00000E+00 Surface No. 2 K = −1.50376E+00, A4= 9.16971E−04, A6 = 9.94477E−06, A8 = −3.69570E−06, A10 = 2.88772E−07,A12 = −9.37503E−09, A14 = 1.08167E−10 Surface No. 3 K = 0.00000E+00, A4= 1.33735E−04, A6 = 8.26828E−06, A8 = −2.36263E−06, A10 = 1.72041E−07,A12 = −5.39358E−09, A14 = 6.14991E−11 Surface No. 5 K = 0.00000E+00, A4= −7.21745E−04, A6 = −2.78703E−06, A8 = −1.01123E−05, A10 = 2.41573E−06,A12 = −3.18270E−07, A14 = 1.76444E−08 Surface No. 14 K = 0.00000E+00, A4= 3.84582E−04, A6 = −4.88167E−05, A8 = 2.35198E−06, A10 = 4.74331E−08,A12 = −3.53285E−09, A14 = 0.00000E+00 Surface No. 15 K = 0.00000E+00, A4= 5.69667E−04, A6 = −3.94000E−05, A8 = 1.79407E−06, A10 = 3.36301E−08,A12 = −2.29056E−09, A14 = 0.00000E+00

TABLE 3 (Various data) Zooming ratio 5.02077 Wide-angle Middle Telephotolimit position limit Focal length 4.2071 10.2045 21.1228 F-number2.90782 5.02380 6.11771 View angle 46.1595 20.5403 10.1174 Image height3.8000 3.8000 3.8000 Overall length 33.0753 29.8672 37.3253 of lenssystem BF 0.42136 0.37974 0.40715 d4 14.3760 4.3000 0.2000 d13 1.77289.7004 21.4167 d15 3.8761 2.8581 2.6724 Zoom lens unit data Lens unitInitial surface Focal length 1 1 −11.10099 2 5 9.35617 3 14 19.50093

Numerical Example 2

The zoom lens system of Numerical Example 2 corresponds to Embodiment 2shown in FIG. 4. Table 4 shows the surface data of the zoom lens systemof Numerical Example 2. Table 5 shows the aspherical data. Table 6 showsvarious data.

TABLE 4 (Surface data) Surface number r d nd vd Object surface ∞  191.71600 1.06000 1.85976 40.6  2* 5.02500 1.73200  3* 8.10500 1.980001.99537 20.7  4 15.41300 Variable  5 4.67900 1.55000 1.80434 40.8  620.06000 0.15000  7 17.38100 1.05000 1.72916 54.7  8 −7.78900 0.010001.56732 42.8  9 −7.78900 0.40000 1.76182 26.6 10 5.54400 0.58300 11*9.60700 1.03000 1.69680 55.5 12* 24.77100 0.40000 13 (Diaphragm) ∞Variable 14* 143.86300 1.40700 1.68863 52.8 15* −14.99700 Variable 16 ∞0.28000 1.51680 64.2 17 ∞ 0.50000 18 ∞ 0.50000 1.51680 64.2 19 ∞ (BF)Image surface ∞

TABLE 5 (Aspherical data) Surface No. 2 K = −1.72393E+00, A4 =8.21522E−04, A6 = 2.55266E−05, A8 = −3.88679E−06, A10 = 2.77924E−07, A12= −9.47533E−09, A14 = 1.16437E−10 Surface No. 3 K = 0.00000E+00, A4 =−2.24219E−04, A6 = 2.10672E−05, A8 = −2.55993E−06, A10 = 1.68943E−07,A12 = −5.44312E−09, A14 = 6.31627E−11 Surface No. 11 K = 0.00000E+00, A4= −1.79281E−03, A6 = −2.82240E−04, A8 = 1.33862E−05, A10 = 7.24137E−06,A12 = 0.00000E+00, A14 = 0.00000E+00 Surface No. 12 K = 0.00000E+00, A4= 8.20695E−04, A6 = −3.73734E−05, A8 = −4.11489E−07, A10 = 1.63224E−05,A12 = 0.00000E+00, A14 = 0.00000E+00 Surface No. 14 K = 0.00000E+00, A4= −1.43793E−03, A6 = 6.22989E−05, A8 = −3.57284E−06, A10 = 4.27742E−08,A12 = 1.29183E−09, A14 = 0.00000E+00 Surface No. 15 K = 0.00000E+00, A4= −1.03151E−03, A6 = −6.84282E−06, A8 = 2.21877E−06, A10 = −1.02480E−07,A12 = 1.11563E−09, A14 = 0.00000E+00

TABLE 6 (Various data) Zooming ratio 4.78728 Wide-angle Middle Telephotolimit position limit Focal length 4.5625 10.3339 21.8419 F-number2.91681 4.41216 6.27025 View angle 43.7744 20.6796 9.7181 Image height3.8000 3.8000 3.8000 Overall length 32.9851 26.5722 37.4677 of lenssystem BF 0.42089 0.40791 0.39091 d4 13.9363 2.2741 0.2000 d13 2.42434.3279 21.6993 d15 3.5716 6.9303 2.5455 Zoom lens unit data Lens unitInitial surface Focal length 1 1 −11.49994 2 5 9.44980 3 14 19.79358

Numerical Example 3

The zoom lens system of Numerical Example 3 corresponds to Embodiment 3shown in FIG. 7. Table 7 shows the surface data of the zoom lens systemof Numerical Example 3. Table 8 shows the aspherical data. Table 9 showsvarious data.

TABLE 7 (Surface data) Surface number r d nd vd Object surface ∞  1*140.23000 1.06000 1.89816 34.5  2* 5.45300 1.73200  3* 9.42700 1.980002.13854 17.8  4 17.36000 Variable  5* 4.99100 1.55000 1.80434 40.8  6117.92500 0.15000  7 12.94200 1.05000 1.72916 54.7  8 −13.72800 0.010001.56732 42.8  9 −13.72800 0.40000 1.76182 26.6 10 3.74800 0.58300 1120.43300 1.03000 1.69680 55.5 12 −21.48900 0.40000 13 (Diaphragm) ∞Variable 14* −116.08400 1.40700 1.68863 52.8 15* −12.26900 Variable 16 ∞0.28000 1.51680 64.2 17 ∞ 0.50000 18 ∞ 0.50000 1.51680 64.2 19 ∞ (BF)Image surface ∞

TABLE 8 Aspherical data) Surface No. 1 K = 0.00000E+00, A4 =−5.16032E−06, A6 = 1.36006E−06, A8 = −2.35032E−08, A10 = 9.64467E−12,A12 = 0.00000E+00, A14 = 0.00000E+00 Surface No. 2 K = −1.54603E+00, A4= 8.66310E−04, A6 = 1.05013E−05, A8 = −3.56556E−06, A10 = 2.87567E−07,A12 = −9.59572E−09, A14 = 1.13274E−10 Surface No. 3 K = 0.00000E+00, A4= 5.82564E−05, A6 = 1.23467E−05, A8 = −2.44842E−06, A10 = 1.70937E−07,A12 = −5.28376E−09, A14 = 6.04276E−11 Surface No. 5 K = 0.00000E+00, A4= −6.59982E−04, A6 = −1.07316E−05, A8 = −7.67478E−06, A10 = 2.20031E−06,A12 = −3.14693E−07, A14 = 1.71160E−08 Surface No. 14 K = 0.00000E+00, A4= 3.98783E−04, A6 = −4.87903E−05, A8 = 2.32347E−06, A10 = 4.49831E−08,A12 = −3.64603E−09, A14 = 0.00000E+00 Surface No. 15 K = 0.00000E+00, A4= 6.66651E−04, A6 = −6.35825E−05, A8 = 3.80613E−06, A10 = −2.17291E−08,A12 = −2.43698E−09, A14 = 0.00000E+00

TABLE 9 (Various data) Zooming ratio 4.75067 Wide-angle Middle Telephotolimit position limit Focal length 4.5762 10.2956 21.7403 F-number2.90973 4.76492 6.12812 View angle 43.6578 20.3579 9.8270 Image height3.8000 3.8000 3.8000 Overall length 32.9778 29.9914 37.7234 of lenssystem BF 0.40883 0.36012 0.36629 d4 13.7226 4.3000 0.2000 d13 2.42239.4455 21.9297 d15 3.7921 3.2538 2.5954 Zoom lens unit data Lens unitInitial surface Focal length 1 1 −11.37494 2 5 9.50394 3 14 19.81261

Numerical Example 4

The zoom lens system of Numerical Example 4 corresponds to Embodiment 4shown in FIG. 10. Table 10 shows the surface data of the zoom lenssystem of Numerical Example 4. Table 11 shows the aspherical data. Table12 shows various data.

TABLE 10 (Surface data) Surface number r d nd vd Object surface ∞  1*277.61100 1.06000 1.80470 41.0  2* 5.18600 1.73200  3* 9.15000 1.980001.99537 20.7  4 17.36000 Variable  5* 5.00400 1.55000 1.80434 40.8  6117.92500 0.15000  7 12.83700 1.05000 1.72916 54.7  8 −16.64100 0.010001.56732 42.8  9 −16.64100 0.40000 1.76182 26.6 10 3.74800 0.58300 1119.27500 1.03000 1.69680 55.5 12 −23.38700 0.40000 13 (Diaphragm) ∞Variable 14* −116.08400 1.40700 1.68863 52.8 15* −12.26800 Variable 16 ∞0.28000 1.51680 64.2 17 ∞ 0.50000 18 ∞ 0.50000 1.51680 64.2 19 ∞ (BF)Image surface ∞

TABLE 11 (Aspherical data) Surface No. 1 K = 0.00000E+00, A4 =−5.16032E−06, A6 = 1.36006E−06, A8 = −2.35032E−08, A10 = 9.64467E−12,A12 = 0.00000E+00, A14 = 0.00000E+00 Surface No. 2 K = −1.36045E+00, A4= 9.62829E−04, A6 = 9.75296E−06, A8 = −3.60697E−06, A10 = 2.88964E−07,A12 = −9.50399E−09, A14 = 1.08374E−10 Surface No. 3 K = 0.00000E+00, A4= 1.46718E−04, A6 = 9.99932E−06, A8 = −2.39751E−06, A10 = 1.71641E−07,A12 = −5.32077E−09, A14 = 5.98708E−11 Surface No. 5 K = 0.00000E+00, A4= −6.52447E−04, A6 = −7.02093E−06, A8 = −1.00791E−05, A10 = 2.75597E−06,A12 = −3.51282E−07, A14 = 1.65967E−08 Surface No. 14 K = 0.00000E+00, A4= 3.98783E−04, A6 = −4.87903E−05, A8 = 2.32347E−06, A10 = 4.49831E−08,A12 = −3.64603E−09, A14 = 0.00000E+00 Surface No. 15 K = 0.00000E+00, A4= 6.34167E−04, A6 = −6.11751E−05, A8 = 3.80911E−06, A10 = −3.34184E−08,A12 = −2.00676E−09, A14 = 0.00000E+00

TABLE 12 (Various data) Zooming ratio 4.74438 Wide-angle MiddleTelephoto limit position limit Focal length 4.5794 10.3078 21.7266F-number 2.91050 4.77133 6.13310 View angle 43.5230 20.3763 9.8525 Imageheight 3.8000 3.8000 3.8000 Overall length 32.9845 30.0066 37.7343 oflens system BF 0.41553 0.37528 0.37716 d4 13.7226 4.3000 0.2000 d132.4384 9.4758 21.9238 d15 3.7760 3.2235 2.6013 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −11.37119 2 5 9.50694 3 1419.81081

Numerical Example 5

The zoom lens system of Numerical Example 5 corresponds to Embodiment 5shown in FIG. 13. Table 13 shows the surface data of the zoom lenssystem of Numerical Example 5. Table 14 shows the aspherical data. Table15 shows various data.

TABLE 13 (Surface data) Surface number r d nd vd Object surface ∞  1*277.61100 1.06000 1.80470 41.0  2* 5.18600 1.73200  3* 9.15400 1.980001.99537 20.7  4 17.36000 Variable  5* 5.09400 1.55000 1.87290 40.8  6117.92500 0.15000  7 16.28000 1.05000 1.72916 54.7  8 −13.60500 0.010001.56732 42.8  9 −13.60500 0.40000 1.76182 26.6 10 3.74800 0.58300 1128.27400 1.03000 1.69680 55.5 12 −16.70500 0.40000 13 (Diaphragm) ∞Variable 14* −116.08400 1.40700 1.68863 52.8 15* −12.24500 Variable 16 ∞0.28000 1.51680 64.2 17 ∞ 0.50000 18 ∞ 0.50000 1.51680 64.2 19 ∞ (BF)Image surface ∞

TABLE 14 (Aspherical data) Surface No. 1 K = 0.00000E+00, A4 =−5.16032E−06, A6 = 1.36006E−06, A8 = −2.35032E−08, A10 = 9.64467E−12,A12 = 0.00000E+00, A14 = 0.00000E+00 Surface No. 2 K = −1.21146E+00, A4= 9.42719E−04, A6 = 8.22480E−06, A8 = −3.73153E−06, A10 = 2.89294E−07,A12 = −9.56885E−09, A14 = 1.15064E−10 Surface No. 3 K = 0.00000E+00, A4= 1.96871E−04, A6 = 9.09412E−06, A8 = −2.42115E−06, A10 = 1.68578E−07,A12 = −5.27161E−09, A14 = 6.24497E−11 Surface No. 5 K = 0.00000E+00, A4= −5.89690E−04, A6 = −2.66456E−05, A8 = −4.67652E−06, A10 = 2.49299E−06,A12 = −4.37504E−07, A14 = 2.60253E−08 Surface No. 14 K = 0.00000E+00, A4= 3.98783E−04, A6 = −4.87903E−05, A8 = 2.32347E−06, A10 = 4.49831E−08,A12 = −3.64603E−09, A14 = 0.00000E+00 Surface No. 15 K = 0.00000E+00, A4= 4.95733E−04, A6 = −5.52926E−05, A8 = 4.07254E−06, A10 = −8.39574E−08,A12 = −3.60474E−10, A14 = 0.00000E+00

TABLE 15 (Various data) Zooming ratio 4.73379 Wide-angle MiddleTelephoto limit position limit Focal length 4.5814 10.3126 21.6875F-number 2.90996 4.76998 6.12631 View angle 43.6298 20.5699 9.9939 Imageheight 3.8000 3.8000 3.8000 Overall length 32.9849 30.0104 37.7589 oflens system BF 0.41591 0.37912 0.40176 d4 13.7226 4.3000 0.2000 d132.4562 9.4832 21.8879 d15 3.7582 3.2161 2.6372 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −11.36300 2 5 9.50654 3 1419.76931

Numerical Example 6

The zoom lens system of Numerical Example 6 corresponds to Embodiment 6shown in FIG. 16. Table 16 shows the surface data of the zoom lenssystem of Numerical Example 6. Table 17 shows the aspherical data. Table18 shows various data.

TABLE 16 (Surface data) Surface number r d nd vd Object surface ∞  1*177.47800 1.03900 1.85976 40.6  2* 6.63600 2.05700  3* 11.13100 2.324001.99537 20.7  4 21.12900 Variable  5* 6.03400 1.85100 1.80434 40.8  6143.52700 0.20100  7 15.89500 1.28000 1.72916 54.7  8 −20.09100 0.012001.56732 42.8  9 −20.09100 0.47900 1.76182 26.6 10 4.56200 0.74600 1124.99300 1.11300 1.69680 55.5 12 −26.97000 0.48700 13(Diaphragm) ∞Variable 14* −141.28500 1.53800 1.68863 52.8 15* −14.74800 Variable 16 ∞0.34100 1.51680 64.2 17 ∞ 0.60900 18 ∞ 0.60900 1.51680 64.2 19 ∞ (BF)Image surface ∞

TABLE 17 (Aspherical data) Surface No. 1 K = 0.00000E+00, A4 =−2.86219E−06, A6 = 5.09247E−07, A8 = −5.94077E−09, A10 = 1.64570E−12,A12 = 0.00000E+00, A14 = 0.00000E+00 Surface No. 2 K = −1.53666E+00, A4= 5.02282E−04, A6 = 4.46163E−06, A8 = −9.10715E−07, A10 = 4.91821E−08,A12 = −1.09034E−09, A14 = 8.46522E−12 Surface No. 3 K = 0.00000E+00, A4= 5.74073E−05, A6 = 3.98544E−06, A8 = −6.02600E−07, A10 = 2.93515E−08,A12 = −6.16876E−10, A14 = 4.72214E−12 Surface No. 5 K = 0.00000E+00, A4= −3.87012E−04, A6 = 1.94856E−06, A8 = −3.17953E−06, A10 = 4.47726E−07,A12 = −3.24123E−08, A14 = 9.30481E−10 Surface No. 14 K = 0.00000E+00, A4= 2.21186E−04, A6 = −1.82685E−05, A8 = 5.87291E−07, A10 = 7.67561E−09,A12 = −4.19983E−10, A14 = 0.00000E+00 Surface No. 15 K = 0.00000E+00, A4= 3.95412E−04, A6 = −2.36935E−05, A8 = 8.28888E−07, A10 = 3.84189E−09,A12 = −4.16995E−10, A14 = 0.00000E+00

TABLE 18 (Various data) Zooming ratio 4.78219 Wide-angle MiddleTelephoto limit position limit Focal length 5.5419 12.5134 26.5024F-number 2.88513 4.73316 6.09875 View angle 43.7864 20.3478 9.7989 Imageheight 4.6250 4.6250 4.6250 Overall length 39.4596 35.8400 45.2842 oflens system BF 0.50832 0.46420 0.50531 d4 16.7018 5.2335 0.2434 d132.9482 11.5357 26.7513 d15 4.6153 3.9206 3.0982 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −13.88579 2 5 11.53034 3 1423.79460

Numerical Example 7

The zoom lens system of Numerical Example 7 corresponds to Embodiment 7shown in FIG. 19. Table 19 shows the surface data of the zoom lenssystem of Numerical Example 7. Table 20 shows the aspherical data. Table21 shows various data.

TABLE 19 (Surface data) Surface number r d nd vd Object surface ∞  1126.42600 1.06000 1.86000 40.6  2* 5.72700 1.53700  3* 8.95800 1.776001.99537 20.7  4 17.36000 Variable  5* 5.19400 1.56100 1.80434 40.8  6377.10900 0.30000  7 17.42100 1.06600 1.72916 54.7  8 −13.83000 0.010001.56732 42.8  9 −13.83000 0.40000 1.76182 26.6 10 4.00000 0.58300 1119.73300 1.07700 1.69680 55.5 12 −23.72700 0.40000 13(Diaphragm) ∞Variable 14* −1047.51300 1.40700 1.74993 45.4 15* −14.88700 Variable 16∞ 0.28000 1.51680 64.2 17 ∞ 0.50000 18 ∞ 0.50000 1.51680 64.2 19 ∞ (BF)Image surface ∞

TABLE 20 (Aspherical data) Surface No. 2 K = −1.57344E+00, A4 =7.46340E−04, A6 = 1.88232E−06, A8 = −3.37126E−06, A10 = 2.89498E−07, A12= −9.69126E−09, A14 = 1.14218E−10 Surface No. 3 K = 0.00000E+00, A4 =6.08925E−05, A6 = 2.83846E−06, A8 = −2.14698E−06, A10 = 1.72132E−07, A12= −5.49899E−09, A14 = 6.19799E−11 Surface No. 5 K = 0.00000E+00, A4 =−5.98636E−04, A6 = −2.84764E−06, A8 = −8.39427E−06, A10 = 2.21918E−06,A12 = −2.87429E−07, A14 = 1.45836E−08 Surface No. 14 K = 0.00000E+00, A4= −1.30794E−04, A6 = −9.53762E−06, A8 = −1.31083E−06, A10 = 1.80961E−07,A12 = −4.51916E−09, A14 = 0.00000E+00 Surface No. 15 K = 0.00000E+00, A4= 1.09118E−04, A6 = −3.68938E−05, A8 = 2.09767E−06, A10 = −3.35203E−08,A12 = 5.68690E−10, A14 = 0.00000E+00

TABLE 21 (Various data) Zooming ratio 4.61126 Wide-angle MiddleTelephoto limit position limit Focal length 5.1178 11.0963 23.5995F-number 2.90501 4.68134 6.13237 View angle 39.2002 18.9429 9.0829 Imageheight 3.8000 3.8000 3.8000 Overall length 33.5786 30.7415 38.3943 oflens system BF 0.41039 0.37079 0.37158 d4 14.1000 4.7084 0.2000 d132.4138 9.8111 22.8264 d15 4.1974 3.3942 2.5393 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −12.85293 2 5 10.12689 3 1420.12562

Numerical Example 8

The zoom lens system of Numerical Example 8 corresponds to Embodiment 8shown in FIG. 22. Table 22 shows the surface data of the zoom lenssystem of Numerical Example 8. Table 23 shows the aspherical data. Table24 shows various data.

TABLE 22 (Surface data) Surface number r d nd vd Object surface ∞  1*133.91200 1.06000 1.85976 40.6  2* 5.42900 1.73200  3* 9.15600 1.980001.99537 20.7  4 17.36000 Variable  5* 4.97400 1.55000 1.80434 40.8  6117.92500 0.15000  7 13.33900 1.05000 1.72916 54.7  8 −20.65000 0.010001.56732 42.8  9 −20.65000 0.40000 1.76182 26.6 10 3.74800 0.58300 1117.95000 1.03000 1.69680 55.5 12 −25.80200 0.40000 13(Diaphragm) ∞Variable 14* −116.08400 1.40700 1.68863 52.8 15* −12.28300 Variable 16 ∞0.28000 1.51680 64.2 17 ∞ 0.50000 18 ∞ 0.50000 1.51680 64.2 19 ∞ (BF)Image surface ∞

TABLE 23 (Aspherical data) Surface No. 1 K = 0.00000E+00, A4 =−5.52740E−06, A6 = 1.34755E−06, A8 = −2.37945E−08, A10 = 6.53313E−12,A12 = 0.00000E+00, A14 = 0.00000E+00 Surface No. 2 K = −1.51232E+00, A4= 9.13792E−04, A6 = 1.00193E−05, A8 = −3.69775E−06, A10 = 2.88686E−07,A12 = −9.37576E−09, A14 = 1.08259E−10 Surface No. 3 K = 0.00000E+00, A4= 1.27176E−04, A6 = 7.89593E−06, A8 = −2.36128E−06, A10 = 1.72237E−07,A12 = −5.38467E−09, A14 = 6.18081E−11 Surface No. 5 K = 0.00000E+00, A4= −7.06960E−04, A6 = −3.25988E−07, A8 = −9.87767E−06, A10 = 2.42687E−06,A12 = −3.19796E−07, A14 = 1.70210E−08 Surface No. 14 K = 0.00000E+00, A4= 3.70421E−04, A6 = −5.43849E−05, A8 = 1.64888E−06, A10 = 1.80901E−09,A12 = −5.31193E−09, A14 = 0.00000E+00 Surface No. 15 K = 0.00000E+00, A4= 5.24695E−04, A6 = −4.63237E−05, A8 = 1.20665E−06, A10 = 4.10694E−09,A12 = −4.23522E−09, A14 = 0.00000E+00

TABLE 24 (Various data) Zooming ratio 5.35662 Wide-angle MiddleTelephoto limit position limit Focal length 4.5928 10.2950 24.6021F-number 2.90896 4.74737 6.91879 View angle 43.5348 20.5052 8.8865 Imageheight 3.8000 3.8000 3.8000 Overall length 32.9479 30.0189 38.9815 oflens system BF 0.40477 0.36130 0.37320 d4 13.7226 4.3000 0.2000 d132.2520 9.2104 24.8417 d15 3.9365 3.5152 0.9346 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −11.42384 2 5 9.55095 3 1419.83788

Numerical Example 9

The zoom lens system of Numerical Example 9 corresponds to Embodiment 9shown in FIG. 25. Table 25 shows the surface data of the zoom lenssystem of Numerical Example 9. Table 26 shows the aspherical data. Table27 shows various data.

TABLE 25 (Surface data) Surface number r d nd vd Object surface ∞  1*102.49100 1.06000 1.85976 40.6  2* 5.38400 1.73200  3* 9.16300 1.980001.99537 20.7  4 17.36000 Variable  5* 4.98100 1.55000 1.80434 40.8  6117.92500 0.15000  7 13.41700 1.05000 1.72916 54.7  8 −22.36400 0.010001.56732 42.8  9 −22.36400 0.40000 1.76182 26.6 10 3.74800 0.58300 1117.49900 1.03000 1.69680 55.5 12 −27.91500 0.40000 13(Diaphragm) ∞Variable 14* −116.08400 1.40700 1.68863 52.8 15* −12.30700 Variable 16 ∞0.28000 1.51680 64.2 17 ∞ 0.50000 18 ∞ 0.50000 1.51680 64.2 19 ∞ (BF)Image surface ∞

TABLE 26 (Aspherical data) Surface No. 1 K = 0.00000E+00, A4 =−9.58085E−06, A6 = 1.28804E−06, A8 = −2.45481E−08, A10 = −7.28916E−12,A12 = 0.00000E+00, A14 = 0.00000E+00 Surface No. 2 K = −1.52889E+00, A4= 9.08403E−04, A6 = 1.00563E−05, A8 = −3.70044E−06, A10 = 2.88590E−07,A12 = −9.37676E−09, A14 = 1.08272E−10 Surface No. 3 K = 0.00000E+00, A4= 1.17643E−04, A6 = 7.85565E−06, A8 = −2.35722E−06, A10 = 1.72387E−07,A12 = −5.38158E−09, A14 = 6.18075E−11 Surface No. 5 K = 0.00000E+00, A4= −6.97064E−04, A6 = 1.09037E−06, A8 = −9.75291E−06, A10 = 2.43347E−06,A12 = −3.20810E−07, A14 = 1.65049E−08 Surface No. 14 K = 0.00000E+00, A4= 3.07888E−04, A6 = −5.28977E−05, A8 = 1.68576E−06, A10 = 1.34836E−09,A12 = 1.29575E−10, A14 = 0.00000E+00 Surface No. 15 K = 0.00000E+00, A4= 5.47465E−04, A6 = −5.13331E−05, A8 = 1.07290E−06, A10 = 4.69963E−08,A12 = −1.02369E−09, A14 = 0.00000E+00

TABLE 27 (Various data) Zooming ratio 5.52871 Wide-angle MiddleTelephoto limit position limit Focal length 4.6725 10.3808 25.8329F-number 2.94730 4.77127 7.24009 View angle 42.6119 20.1748 8.3929 Imageheight 3.8000 3.8000 3.8000 Overall length 33.0804 30.2033 40.0342 oflens system BF 0.40551 0.36552 0.38499 d4 13.7226 4.3000 0.2000 d132.3123 9.1093 26.0977 d15 4.0080 3.7965 0.7195 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −11.50512 2 5 9.64428 3 1419.88122

Numerical Example 10

The zoom lens system of Numerical Example 10 corresponds to Embodiment10 shown in FIG. 28. Table 28 shows the surface data of the zoom lenssystem of Numerical Example 10. Table 29 shows the aspherical data.Table 30 shows various data.

TABLE 28 (Surface data) Surface number r d nd vd Object surface ∞  1*76.42751 1.00000 1.80470 41.0  2* 6.64817 1.48000  3 7.75447 1.600001.92286 20.9  4 10.50123 Variable  5* 5.53570 1.50000 1.80434 40.8  6−674.52140 0.30000  7 10.79499 1.10000 1.72916 54.7  8 −15.59648 0.010001.56732 42.8  9 −15.59648 0.40000 1.76182 26.6 10 4.00000 0.64000 1140.99489 1.10000 1.80146 40.2 12 −40.99489 0.30000 13(Diaphragm) ∞Variable 14 −53.29376 1.33000 1.68863 52.8 15* −12.58029 Variable 16 ∞0.28000 1.51680 64.2 17 ∞ 0.50000 18 ∞ 0.50000 1.51680 64.2 19 ∞ (BF)Image surface ∞

TABLE 29 (Aspherical data) Surface No. 1 K = 0.00000E+00, A4 =5.76012E−05, A6 = 8.73773E−07, A8 = 0.00000E+00, A10 = 0.00000E+00, A12= 0.00000E+00, A14 = 0.00000E+00 Surface No. 2 K = −1.43352E+00, A4 =6.73429E−04, A6 = −1.70436E−07, A8 = 1.25757E−07, A10 = 3.13106E−08, A12= −1.68591E−09, A14 = 3.01568E−11 Surface No. 5 K = 0.00000E+00, A4 =−4.98245E−04, A6 = 4.02131E−06, A8 = −1.18557E−05, A10 = 2.68271E−06,A12 = −2.79815E−07, A14 = 1.08519E−08 Surface No. 15 K = 0.00000E+00, A4= −3.33092E−05, A6 = 2.24255E−05, A8 = −2.42474E−06, A10 = 1.37066E−07,A12 = −2.99454E−09, A14 = 0.00000E+00

TABLE 30 (Various data) Zooming ratio 4.72712 Wide-angle MiddleTelephoto limit position limit Focal length 6.0022 13.0594 28.3731F-number 3.44370 5.55842 6.33102 View angle 34.9812 16.3974 7.6997 Imageheight 3.8000 3.8000 3.8000 Overall length 33.8543 31.0006 39.9649 oflens system BF 0.46119 0.40554 0.37123 d4 14.2069 4.6883 0.2000 d132.9360 10.1917 24.3632 d15 4.2102 3.6751 2.9905 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −13.93476 2 5 10.14370 3 1423.59911

Numerical Example 11

The zoom lens system of Numerical Example 11 corresponds to Embodiment11 shown in FIG. 31. Table 31 shows the surface data of the zoom lenssystem of Numerical Example 11. Table 32 shows the aspherical data.Table 33 shows various data.

TABLE 31 (Surface data) Surface number r d nd vd Object surface ∞  1*59.05000 1.06000 1.85280 39.0  2* 5.46200 1.50400  3* 8.60600 1.750001.99537 20.7  4 14.38100 Variable  5* 4.36700 2.50000 1.80359 40.8  6−67.53500 0.00000  7 −67.53500 0.40000 1.80518 25.5  8 3.80100 0.47700 9 12.23200 1.14400 1.77250 49.6 10 −16.77300 0.30000 11(Diaphragm) ∞Variable 12* 145.66100 1.33400 1.60602 57.4 13* −11.92000 Variable 14 ∞0.78000 1.51680 64.2 15 ∞ (BF) Image surface ∞

TABLE 32 (Aspherical data) Surface No. 1 K = 0.00000E+00, A4 =3.04043E−06, A6 = 8.38044E−08, A8 = 3.68394E−10, A10 = 1.11988E−11, A12= 0.00000E+00, A14 = 0.00000E+00 Surface No. 2 K = −1.14246E+00, A4 =9.52084E−04, A6 = 1.16305E−05, A8 = −3.37781E−06, A10 = 2.84249E−07, A12= −9.68993E−09, A14 = 1.17859E−10 Surface No. 3 K = 0.00000E+00, A4 =2.77587E−04, A6 = 7.49692E−06, A8 = −2.20563E−06, A10 = 1.70898E−07, A12= −5.50993E−09, A14 = 6.41238E−11 Surface No. 5 K = −2.43504E−01, A4 =−3.61300E−04, A6 = 1.01452E−05, A8 = −3.95475E−06, A10 = 2.05823E−07,A12 = 0.00000E+00, A14 = 0.00000E+00 Surface No. 12 K = 0.00000E+00, A4= −3.11808E−04, A6 = 1.60552E−05, A8 = −9.71795E−07, A10 = 2.22891E−07,A12 = −2.85194E−09, A14 = 0.00000E+00 Surface No. 13 K = 0.00000E+00, A4= 3.67285E−05, A6 = −1.48330E−05, A8 = 2.12933E−06, A10 = 5.52463E−08,A12 = 2.05349E−09, A14 = 0.00000E+00

TABLE 33 (Various data) Zooming ratio 4.70964 Wide-angle MiddleTelephoto limit position limit Focal length 4.2182 10.9848 19.8661F-number 2.91810 4.94788 6.15928 View angle 45.5442 19.1934 10.7826Image height 3.8000 3.8000 3.8000 Overall length 32.2531 29.2032 33.9277of lens system BF 0.89844 0.85770 0.89904 d4 14.1856 3.9014 0.2000 d112.1610 11.4996 19.9321 d13 3.7591 1.6955 1.6476 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −11.81909 2 5 9.29435 3 1218.23972

Numerical Example 12

The zoom lens system of Numerical Example 12 corresponds to Embodiment12 shown in FIG. 34. Table 34 shows the surface data of the zoom lenssystem of Numerical Example 12. Table 35 shows the aspherical data.Table 36 shows various data.

TABLE 34 (Surface data) Surface number r d nd vd Object surface ∞  1*48.20000 1.06000 1.85280 39.0  2* 5.40600 1.50400  3* 8.59700 1.750001.99537 20.7  4 14.38100 Variable  5* 4.37800 2.50000 1.80359 40.8  6−74.88600 0.00000  7 −74.88600 0.40000 1.80518 25.5  8 3.79800 0.47700 9 12.73200 1.14400 1.77250 49.6 10 −16.77300 0.30000 11(Diaphragm) ∞Variable 12* 147.88000 1.33400 1.60602 57.4 13* −13.66400 Variable 14 ∞0.78000 1.51680 64.2 15 ∞ (BF) Image surface ∞

TABLE 35 (Aspherical data) Surface No. 1 K = 0.00000E+00, A4 =3.27932E−07, A6 = −4.95347E−08, A8 = 0.00000E+00, A10 = 0.00000E+00, A12= 0.00000E+00, A14 = 0.00000E+00 Surface No. 2 K = −1.15549E+00, A4 =9.45387E−04, A6 = 1.00448E−05, A8 = −3.40038E−06, A10 = 2.83776E−07, A12= −9.69584E−09, A14 = 1.17520E−10 Surface No. 3 K = 0.00000E+00, A4 =2.60379E−04, A6 = 6.67780E−06, A8 = −2.20806E−06, A10 = 1.70845E−07, A12= −5.50808E−09, A14 = 6.38203E−11 Surface No. 5 K = −2.33677E−01, A4 =−3.37270E−04, A6 = 5.87427E−06, A8 = −3.18469E−06, A10 = 2.15900E−07,A12 = 0.00000E+00, A14 = 0.00000E+00 Surface No. 12 K = 0.00000E+00, A4= −3.84815E−04, A6 = 1.89763E−05, A8 = −9.66009E−07, A10 = 2.07197E−07,A12 = −2.90921E−09, A14 = 0.00000E+00 Surface No. 13 K = 0.00000E+00, A4= −8.25767E−05, A6 = −1.37702E−05, A8 = 1.82480E−06, A10 = 5.49510E−08,A12 = 2.05096E−09, A14 = 0.00000E+00

TABLE 36 (Various data) Zooming ratio 4.66639 Wide-angle MiddleTelephoto limit position limit Focal length 4.5138 11.0107 21.0630F-number 2.92234 4.74573 6.11588 View angle 42.9660 19.1684 10.1843Image height 3.8000 3.8000 3.8000 Overall length 32.9135 29.6175 34.9167of lens system BF 0.89634 0.86350 0.87175 d4 14.3758 4.2462 0.2000 d112.4307 11.1258 20.7413 d13 3.9617 2.1330 1.8547 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −12.09887 2 5 9.49321 3 1220.70451

Numerical Example 13

The zoom lens system of Numerical Example 13 corresponds to Embodiment13 shown in FIG. 37. Table 37 shows the surface data of the zoom lenssystem of Numerical Example 13. Table 38 shows the aspherical data.Table 39 shows various data.

TABLE 37 (Surface data) Surface number r d nd vd Object surface ∞  143.56000 1.06000 1.85280 39.0  2* 5.54700 1.50400  3* 8.64600 1.750001.99537 20.7  4 14.38100 Variable  5* 4.39600 2.50000 1.80359 40.8  6−115.81400 0.00000  7 −115.81400 0.40000 1.80518 25.5  8 3.79300 0.47700 9 14.69100 1.14400 1.77250 49.6 10 −16.77300 0.30000 11(Diaphragm) ∞Variable 12* 79.01900 1.33400 1.60602 57.4 13* −14.68200 Variable 14 ∞0.78000 1.51680 64.2 15 ∞ (BF) Image surface ∞

TABLE 38 (Aspherical data) Surface No. 2 K = −1.11955E+00, A4 =9.72575E−04, A6 = 5.28421E−06, A8 = −3.33441E−06, A10 = 2.83170E−07, A12= −9.76538E−09, A14 = 1.18913E−10 Surface No. 3 K = 0.00000E+00, A4 =2.96666E−04, A6 = 4.70617E−06, A8 = −2.23721E−06, A10 = 1.71468E−07, A12= −5.48027E−09, A14 = 6.24905E−11 Surface No. 5 K = −2.21945E−01, A4 =−3.12123E−04, A6 = 4.68008E−06, A8 = −3.33833E−06, A10 = 2.42304E−07,A12 = 0.00000E+00, A14 = 0.00000E+00 Surface No. 12 K = 0.00000E+00, A4= −5.07858E−04, A6 = 1.16247E−05, A8 = −1.11086E−06, A10 = 1.55636E−07,A12 = −9.60910E−10, A14 = 0.00000E+00 Surface No. 13 K = 0.00000E+00, A4= −4.92557E−04, A6 = −2.33283E−06, A8 = 7.70699E−07, A10 = 4.54566E−08,A12 = 2.00412E−09, A14 = 0.00000E+00

TABLE 39 (Various data) Zooming ratio 4.65926 Wide-angle MiddleTelephoto limit position limit Focal length 4.9826 11.0055 23.2154F-number 2.96523 4.88875 6.11703 View angle 38.2008 18.4701 8.9029 Imageheight 3.6000 3.6000 3.6000 Overall length 33.4459 31.3516 38.0142 oflens system BF 0.90869 0.86454 0.89389 d4 14.2459 5.5449 0.2000 d112.6393 11.7655 23.1698 d13 4.4030 1.9277 2.5015 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −12.88044 2 5 10.10697 3 1220.54116

Numerical Example 14

The zoom lens system of Numerical Example 14 corresponds to Embodiment14 shown in FIG. 40. Table 40 shows the surface data of the zoom lenssystem of Numerical Example 14. Table 41 shows the aspherical data.Table 42 shows various data.

TABLE 40 (Surface data) Surface number r d nd vd Object surface ∞  1*65.26800 1.06000 1.85280 39.0  2* 5.43100 1.50400  3* 8.75800 1.750001.99537 20.7  4 14.38100 Variable  5* 4.34800 2.50000 1.80359 40.8  6154.36000 0.00000  7 154.36000 0.40000 1.80518 25.5  8 3.78600 0.47700 9 12.80100 1.14400 1.77250 49.6 10 −16.77300 0.30000 11(Diaphragm) ∞Variable 12* −21.93400 1.33400 1.60602 57.4 13* −8.75000 Variable 14 ∞0.78000 1.51680 64.2 15 ∞ (BF) Image surface ∞

TABLE 41 (Aspherical data) Surface No. 1 K = 0.00000E+00, A4 =1.92866E−06, A6 = −2.59806E−07, A8 = 0.00000E+00, A10 = 0.00000E+00, A12= 0.00000E+00, A14 = 0.00000E+00 Surface No. 2 K = −1.12457E+00, A4 =9.65240E−04, A6 = 7.72275E−06, A8 = −3.45452E−06, A10 = 2.84301E−07, A12= −9.70703E−09, A14 = 1.17484E−10 Surface No. 3 K = 0.00000E+00, A4 =2.90216E−04, A6 = 7.30560E−06, A8 = −2.22065E−06, A10 = 1.70191E−07, A12= −5.52242E−09, A14 = 6.43532E−11 Surface No. 5 K = −2.32994E−01, A4 =−3.37630E−04, A6 = 2.79870E−06, A8 = −3.71831E−06, A10 = 3.04308E−07,A12 = 0.00000E+00, A14 = 0.00000E+00 Surface No. 12 K = 0.00000E+00, A4= −3.98270E−04, A6 = 1.52053E−05, A8 = −8.64592E−07, A10 = 2.48416E−07,A12 = −4.83203E−09, A14 = 0.00000E+00 Surface No. 13 K = 0.00000E+00, A4= 1.48124E−04, A6 = −1.28334E−05, A8 = 2.23453E−06, A10 = 2.99201E−08,A12 = 1.47871E−09, A14 = 0.00000E+00

TABLE 42 (Various data) Zooming ratio 5.64043 Wide-angle MiddleTelephoto limit position limit Focal length 4.5204 11.0121 25.4968F-number 2.92132 5.03801 7.49395 View angle 41.3621 18.1278 7.9812 Imageheight 3.6000 3.6000 3.6000 Overall length 33.3391 30.6877 39.6399 oflens system BF 0.90466 0.88115 0.85890 d4 14.3758 4.8086 0.2000 d112.2899 11.5361 25.6839 d13 4.5197 2.2129 1.6481 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −11.17647 2 5 9.42887 3 1223.13762

Numerical Example 15

The zoom lens system of Numerical Example 15 corresponds to Embodiment15 shown in FIG. 43. Table 43 shows the surface data of the zoom lenssystem of Numerical Example 15. Table 44 shows the aspherical data.Table 45 shows various data.

TABLE 43 (Surface data) Surface number r d nd vd Object surface ∞  163.47399 1.06000 1.85280 39.0  2* 6.01722 1.50400  3* 8.59181 1.750001.99537 20.7  4 14.38100 Variable  5* 6.08005 1.56770 1.68863 52.8  6−35.80408 0.10000  7 7.98466 1.48630 1.83481 42.7  8 −7.57710 0.010001.56732 42.8  9 −7.57710 0.40000 1.71736 29.5 10 3.50287 0.9850011(Diaphragm) ∞ Variable 12* −122.39270 1.33400 1.68863 52.8 13*−12.51244 Variable 14 ∞ 0.28000 1.51680 64.2 15 ∞ 0.50000 16 ∞ 0.500001.51680 64.2 17 ∞ (BF) Image surface ∞

TABLE 44 (Aspherical data) Surface No. 2 K = −1.40153E+00, A4 =8.22636E−04, A6 = 7.20741E−06, A8 = −3.32095E−06, A10 = 2.82431E−07, A12= −9.82219E−09, A14 = 1.18759E−10 Surface No. 3 K = 0.00000E+00, A4 =1.68228E−04, A6 = 3.35892E−06, A8 = −2.18948E−06, A10 = 1.71047E−07, A12= −5.51145E−09, A14 = 6.18100E−11 Surface No. 5 K = 0.00000E+00, A4 =−8.68691E−04, A6 = −1.04599E−05, A8 = −4.13399E−07, A10 = −1.71635E−07,A12 = 3.28061E−08, A14 = −1.59341E−09 Surface No. 12 K = 0.00000E+00, A4= 7.33143E−05, A6 = 8.19768E−07, A8 = −1.14709E−06, A10 = 1.69694E−07,A12 = −4.34250E−09, A14 = 0.00000E+00 Surface No. 13 K = 0.00000E+00, A4= 3.98865E−04, A6 = −2.32267E−05, A8 = 1.39281E−06, A10 = 2.04809E−08,A12 = −9.18152E−10, A14 = 0.00000E+00

TABLE 45 (Various data) Zooming ratio 4.69249 Wide-angle MiddleTelephoto limit position limit Focal length 5.3887 11.4765 25.2865F-number 2.90678 4.47443 6.16111 View angle 37.6440 18.1179 8.4394 Imageheight 3.8000 3.8000 3.8000 Overall length 33.2324 28.8126 36.4906 oflens system BF 0.41957 0.34467 0.39309 d4 14.8608 4.6809 0.2000 d112.6360 8.2604 21.7344 d13 3.8390 4.0496 2.6861 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −14.00580 2 5 9.86327 3 1220.13942

Numerical Example 16

The zoom lens system of Numerical Example 16 corresponds to Embodiment16 shown in FIG. 46. Table 46 shows the surface data of the zoom lenssystem of Numerical Example 16. Table 47 shows the aspherical data.Table 48 shows various data.

TABLE 46 (Surface data) Surface number r d nd vd Object surface ∞  167.11508 1.06000 1.85280 39.0  2* 5.93643 1.50400  3* 8.67244 1.750001.99537 20.7  4 14.38100 Variable  5* 6.04644 1.50070 1.68863 52.8  6−31.45638 0.10000  7 8.02778 1.52600 1.83481 42.7  8 −7.47219 0.010001.56732 42.8  9 −7.47219 0.40000 1.71736 29.5 10 3.50287 0.9850011(Diaphragm) ∞ Variable 12* −107.31420 1.33400 1.68863 52.8 13*−12.02005 Variable 14 ∞ 0.28000 1.51680 64.2 15 ∞ 0.50000 16 ∞ 0.500001.51680 64.2 17 ∞ (BF) Image surface ∞

TABLE 47 (Aspherical data) Surface No. 2 K = −1.40725E+00, A4 =8.24033E−04, A6 = 7.65767E−06, A8 = −3.31358E−06, A10 = 2.82628E−07, A12= −9.81656E−09, A14 = 1.18891E−10 Surface No. 3 K = 0.00000E+00, A4 =1.68357E−04, A6 = 3.35244E−06, A8 = −2.18545E−06, A10 = 1.71187E−07, A12= −5.50659E−09, A14 = 6.20096E−11 Surface No. 5 K = 0.00000E+00, A4 =−9.09029E−04, A6 = −1.11663E−05, A8 = −3.76602E−07, A10 = −1.69774E−07,A12 = 3.26901E−08, A14 = −1.59319E−09 Surface No. 12 K = 0.00000E+00, A4= 4.98372E−05, A6 = 2.36765E−05, A8 = −1.16504E−06, A10 = 1.33583E−07,A12 = −4.07360E−09, A14 = 0.00000E+00 Surface No. 13 K = 0.00000E+00, A4= 5.23496E−04, A6 = −1.18940E−05, A8 = 1.57366E−06, A10 = 3.05910E−08,A12 = −2.51680E−09, A14 = 0.00000E+00

TABLE 48 (Various data) Zooming ratio 4.97350 Wide-angle MiddleTelephoto limit position limit Focal length 4.9440 10.9999 24.5887F-number 2.86849 4.47181 6.02934 View angle 40.5984 18.7047 8.5997 Imageheight 3.8000 3.8000 3.8000 Overall length 33.3276 28.0492 36.0296 oflens system BF 0.42910 0.35221 0.38698 d4 15.4234 4.4723 0.2000 d112.6360 7.7519 21.3068 d13 3.3894 4.0230 2.6861 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −13.26565 2 5 9.49125 3 1219.54515

Numerical Example 17

The zoom lens system of Numerical Example 17 corresponds to Embodiment17 shown in FIG. 49. Table 49 shows the surface data of the zoom lenssystem of Numerical Example 17. Table 50 shows the aspherical data.Table 51 shows various data.

TABLE 49 (Surface data) Surface number r d nd vd Object surface ∞  166.99756 1.06000 1.85280 39.0  2* 5.92693 1.50400  3* 8.66891 1.750001.99537 20.7  4 14.38100 Variable  5* 6.04238 1.47300 1.68863 52.8  6−31.84957 0.10000  7 7.97831 1.52260 1.83481 42.7  8 −7.42943 0.010001.56732 42.8  9 −7.42943 0.40000 1.71736 29.5 10 3.50287 0.9850011(Diaphragm) ∞ Variable 12* −124.53680 1.33400 1.68863 52.8 13*−11.63546 Variable 14 ∞ 0.28000 1.51680 64.2 15 ∞ 0.50000 16 ∞ 0.500001.51680 64.2 17 ∞ (BF) Image surface ∞

TABLE 50 (Aspherical data) Surface No. 2 K = −1.40989E+00, A4 =8.22545E−04, A6 = 7.45234E−06, A8 = −3.31504E−06, A10 = 2.82561E−07, A12= −9.82067E−09, A14 = 1.18701E−10 Surface No. 3 K = 0.00000E+00, A4 =1.68883E−04, A6 = 3.36000E−06, A8 = −2.18923E−06, A10 = 1.71073E−07, A12= −5.50897E−09, A14 = 6.19721E−11 Surface No. 5 K = 0.00000E+00, A4 =−9.17209E−04, A6 = −1.14922E−05, A8 = −3.86295E−07, A10 = −1.69119E−07,A12 = 3.29873E−08, A14 = −1.52387E−09 Surface No. 12 K = 0.00000E+00, A4= 3.44434E−05, A6 = 2.52919E−05, A8 = −1.15251E−06, A10 = 1.31557E−07,A12 = −3.96388E−09, A14 = 0.00000E+00 Surface No. 13 K = 0.00000E+00, A4= 5.44445E−04, A6 = −1.16407E−05, A8 = 1.60284E−06, A10 = 3.33080E−08,A12 = −2.54996E−09, A14 = 0.00000E+00

TABLE 51 (Various data) Zooming ratio 4.94889 Wide-angle MiddleTelephoto limit position limit Focal length 4.8230 9.8989 23.8686F-number 2.92673 4.29935 6.02423 View angle 41.2896 20.6747 8.8279 Imageheight 3.8000 3.8000 3.8000 Overall length 33.3145 27.6252 35.5444 oflens system BF 0.42965 0.35867 0.38805 d4 15.5588 5.1363 0.2000 d112.6360 6.7258 20.8516 d13 3.2715 3.9858 2.6861 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −13.24063 2 5 9.45447 3 1218.54849

Numerical Example 18

The zoom lens system of Numerical Example 18 corresponds to Embodiment18 shown in FIG. 52. Table 52 shows the surface data of the zoom lenssystem of Numerical Example 18. Table 53 shows the aspherical data.Table 54 shows various data.

TABLE 52 (Surface data) Surface number r d nd vd Object surface ∞  142.52694 1.06000 1.85280 39.0  2* 5.68093 1.50400  3* 8.67288 1.750001.99537 20.7  4 14.38100 Variable  5* 4.36525 2.50000 1.80359 40.8  6−71.54269 0.40000 1.80518 25.5  7 3.82048 0.47690  8 17.07332 1.144101.77250 49.6  9 −16.77307 0.30000 10(Diaphragm) ∞ Variable 11* −80.548011.33400 1.68863 52.8 12* −11.93863 Variable 13 ∞ 0.28000 1.51680 64.2 14∞ 0.50000 15 ∞ 0.50000 1.51680 64.2 16 ∞ (BF) Image surface ∞

TABLE 53 (Aspherical data) Surface No. 2 K = −1.34333E+00, A4 =8.43676E−04, A6 = 3.59200E−06, A8 = −3.29172E−06, A10 = 2.85355E−07, A12= −9.76033E−09, A14 = 1.18324E−10 Surface No. 3 K = 0.00000E+00, A4 =1.80977E−04, A6 = 4.80208E−06, A8 = −2.19007E−06, A10 = 1.70661E−07, A12= −5.49780E−09, A14 = 6.36027E−11 Surface No. 5 K = −2.27637E−01, A4 =−3.76705E−04, A6 = 2.78981E−05, A8 = −8.69457E−06, A10 = 6.43727E−07,A12 = 0.00000E+00, A14 = 0.00000E+00 Surface No. 11 K = 0.00000E+00, A4= −1.52329E−04, A6 = −2.60128E−06, A8 = −7.83396E−07, A10 = 1.95923E−07,A12 = −3.84055E−09, A14 = 0.00000E+00 Surface No. 12 K = 0.00000E+00, A4= 3.23671E−05, A6 = −1.87291E−05, A8 = 1.47652E−06, A10 = 3.09913E−08,A12 = 7.47159E−10, A14 = 0.00000E+00

TABLE 54 (Various data) Zooming ratio 4.53687 Wide-angle MiddleTelephoto limit position limit Focal length 5.2926 11.4781 24.0120F-number 3.04251 4.88869 6.20669 View angle 36.5361 18.3530 9.0055 Imageheight 3.8000 3.8000 3.8000 Overall length 33.5962 31.4434 38.5006 oflens system BF 0.42600 0.35251 0.38880 d4 14.0464 5.0701 0.2000 d102.6360 11.1355 23.4767 d12 4.7387 3.1363 2.6861 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −13.49971 2 5 10.36991 3 1120.19342

Numerical Example 19

The zoom lens system of Numerical Example 19 corresponds to Embodiment19 shown in FIG. 55. Table 55 shows the surface data of the zoom lenssystem of Numerical Example 19. Table 56 shows the aspherical data.Table 57 shows various data.

TABLE 55 (Surface data) Surface number r d nd vd Object surface ∞  142.70102 1.06000 1.85280 39.0  2* 5.57066 1.50400  3* 8.68434 1.750001.99537 20.7  4 14.38100 Variable  5* 4.39069 2.50000 1.80359 40.8  6−70.26053 0.40000 1.80518 25.5  7 3.79211 0.47690  8 14.95528 1.144101.77250 49.6  9 −16.77307 0.30000 10(Diaphragm) ∞ Variable 11* 75.540351.33400 1.68863 52.8 12* −16.87201 Variable 13 ∞ 0.28000 1.51680 64.2 14∞ 0.50000 15 ∞ 0.50000 1.51680 64.2 16 ∞ (BF) Image surface ∞

TABLE 56 (Aspherical data) Surface No. 2 K = −1.10895E+00, A4 =9.80110E−04, A6 = 5.37935E−06, A8 = −3.31816E−06, A10 = 2.82550E−07, A12= −9.79287E−09, A14 = 1.19194E−10 Surface No. 3 K = 0.00000E+00, A4 =3.16620E−04, A6 = 4.52889E−06, A8 = −2.24766E−06, A10 = 1.71664E−07, A12= −5.47562E−09, A14 = 6.19684E−11 Surface No. 5 K = −2.23619E−01, A4 =−3.15552E−04, A6 = 4.51483E−06, A8 = −3.56603E−06, A10 = 2.70787E−07,A12 = 0.00000E+00, A14 = 0.00000E+00 Surface No. 11 K = 0.00000E+00, A4= −5.09159E−04, A6 = 3.02877E−06, A8 = −1.27336E−06, A10 = 1.46792E−07,A12 = −1.63257E−09, A14 = 0.00000E+00 Surface No. 12 K = 0.00000E+00, A4= −5.90562E−04, A6 = −3.70497E−06, A8 = 3.88633E−07, A10 = 2.62396E−08,A12 = 1.43856E−09, A14 = 0.00000E+00

TABLE 57 (Various data) Zooming ratio 4.64119 Wide-angle MiddleTelephoto limit position limit Focal length 4.9861 11.0001 23.1414F-number 2.95520 4.87262 6.08135 View angle 39.9116 19.5373 9.4812 Imageheight 3.8000 3.8000 3.8000 Overall length 33.4464 31.4551 38.2247 oflens system BF 0.41065 0.34276 0.37653 d4 14.2276 5.5541 0.2000 d102.6360 11.7632 23.2131 d12 4.4231 2.0461 2.6861 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −12.94754 2 5 10.15020 3 1120.14624

Numerical Example 20

The zoom lens system of Numerical Example 20 corresponds to Embodiment20 shown in FIG. 58. Table 58 shows the surface data of the zoom lenssystem of Numerical Example 20. Table 59 shows the aspherical data.Table 60 shows various data.

TABLE 58 (Surface data) Surface number r d nd vd Object surface ∞  135.42244 1.06000 1.85280 39.0  2* 5.32451 1.50400  3* 8.65227 1.750001.99537 20.7  4 14.38100 Variable  5* 4.27762 2.50000 1.80359 40.8  6−494.42940 0.40000 1.80518 25.5  7 3.70655 0.47690  8 17.62745 1.144101.77250 49.6  9 −16.77307 0.30000 10(Diaphragm) ∞ Variable 11* 46.412211.33400 1.68863 52.8 12* −19.53072 Variable 13 ∞ 0.28000 1.51680 64.2 14∞ 0.50000 15 ∞ 0.50000 1.51680 64.2 16 ∞ (BF) Image surface ∞

TABLE 59 (Aspherical data) Surface No. 2 K = −1.02588E+00, A4 =1.00837E−03, A6 = −1.35772E−05, A8 = −2.98948E−06, A10 = 2.92183E−07,A12 = −9.57272E−09, A14 = 1.06236E−10 Surface No. 3 K = 0.00000E+00, A4= 3.49391E−04, A6 = −3.31939E−06, A8 = −2.26288E−06, A10 = 1.85846E−07,A12 = −5.62099E−09, A14 = 5.85455E−11 Surface No. 5 K = −2.28466E−01, A4= −3.11847E−04, A6 = −9.62733E−06, A8 = −9.01185E−08, A10 = 1.56445E−08,A12 = 0.00000E+00, A14 = 0.00000E+00 Surface No. 11 K = 0.00000E+00, A4= −8.40972E−04, A6 = 8.55587E−05, A8 = −5.50326E−06, A10 = 9.49363E−08,A12 = 1.92040E−09, A14 = 0.00000E+00 Surface No. 12 K = 0.00000E+00, A4= −8.48616E−04, A6 = 5.97906E−05, A8 = −1.72782E−06, A10 = −1.09232E−07,A12 = 5.79395E−09, A14 = 0.00000E+00

TABLE 60 (Various data) Zooming ratio 5.67343 Wide-angle MiddleTelephoto limit position limit Focal length 5.2010 12.0508 29.5073F-number 3.08108 5.36923 7.77372 View angle 37.3653 17.8273 7.4457 Imageheight 3.8000 3.8000 3.8000 Overall length 33.5190 33.3381 46.5304 oflens system BF 0.41574 0.34122 0.36643 d4 13.9022 5.5477 0.2000 d102.6360 13.4442 31.5289 d12 4.8160 2.2560 2.6861 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −12.61134 2 5 10.47662 3 1120.12769

Numerical Example 21

The zoom lens system of Numerical Example 21 corresponds to Embodiment21 shown in FIG. 61. Table 61 shows the surface data of the zoom lenssystem of Numerical Example 21. Table 62 shows the aspherical data.Table 63 shows various data.

TABLE 61 (Surface data) Surface number r d nd vd Object surface ∞  1*121.77400 1.35000 1.88300 40.8  2* 4.59300 1.66900  3 7.05800 1.600001.92287 18.9  4 11.92800 Variable  5* 4.18500 2.00000 1.77250 49.6  610.87900 0.50000 1.64769 33.8  7 3.66100 0.48000  8 8.24900 0.500001.76183 26.5  9 3.97900 2.00000 1.60311 60.6 10 −10.51800 0.3000011(Diaphragm) ∞ Variable 12 45.65100 1.60000 1.60311 60.6 13 −23.91400Variable 14 ∞ 1.40000 1.51633 64.1 15 ∞ (BF) Image surface ∞

TABLE 62 (Aspherical data) Surface No. 1 K = 0.00000E+00, A4 =3.18638E−04, A6 = −4.73036E−06, A8 = 3.76995E−08, A10 = 0.00000E+00Surface No. 2 K = −1.47866E+00, A4 = 1.64875E−03, A6 = 1.02150E−05, A8 =−4.99629E−07, A10 = 2.42134E−08 Surface No. 5 K = −4.49065E−01, A4 =−9.97316E−05, A6 = 1.40893E−06, A8 = 0.00000E+00, A10 = 0.00000E+00

TABLE 63 (Various data) Zooming ratio 4.80185 Wide-angle MiddleTelephoto limit position limit Focal length 3.8997 10.4303 18.7259F-number 2.80200 5.33669 6.11778 View angle 46.5205 19.4974 10.9872Image height 3.6000 3.6000 3.6000 Overall length 30.7959 30.3826 37.2037of lens system BF 1.02501 1.00139 1.01023 d4 11.4400 2.9456 0.1500 d111.2672 11.9186 21.1596 d13 3.6647 1.1180 1.4849 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −8.66678 2 5 8.54395 3 12 26.24759

Numerical Example 22

The zoom lens system of Numerical Example 22 corresponds to Embodiment22 shown in FIG. 64. Table 64 shows the surface data of the zoom lenssystem of Numerical Example 22. Table 65 shows the aspherical data.Table 66 shows various data.

TABLE 64 (Surface data) Surface number r d nd vd Object surface ∞  1*54.56700 1.35000 1.88300 40.8  2* 4.76000 1.94200  3 7.01500 1.600001.92287 18.9  4 10.72700 Variable  5* 4.23600 2.00000 1.77250 49.6  69.39300 0.50000 1.64769 33.8  7 3.64800 0.48000  8 8.26300 0.500001.76183 26.5  9 4.00600 2.00000 1.60311 60.6 10 −11.64200 0.3000011(Diaphragm) ∞ Variable 12 34.68300 1.60000 1.60311 60.6 13 −27.64900Variable 14 ∞ 1.40000 1.51633 64.1 15 ∞ (BF) Image surface ∞

TABLE 65 (Aspherical data) Surface No. 1 K = 0.00000E+00, A4 =3.61641E−04, A6 = −5.02438E−06, A8 = 2.59231E−08, A10 = 0.00000E+00Surface No. 2 K = −1.53173E+00, A4 = 1.65738E−03, A6 = 2.09911E−05, A8 =−1.66275E−07, A10 = −3.69650E−09 Surface No. 5 K = −4.39707E−01, A4 =−2.39404E−05, A6 = 2.26135E−06, A8 = 0.00000E+00, A10 = 0.00000E+00

TABLE 66 (Various data) Zooming ratio 4.78672 Wide-angle MiddleTelephoto limit position limit Focal length 4.2681 10.4357 20.4301F-number 2.86927 5.02409 6.20159 View angle 43.4719 19.4769 10.0548Image height 3.6000 3.6000 3.6000 Overall length 31.5753 31.0990 39.8252of lens system BF 1.02817 1.00170 1.03473 d4 11.4400 2.8570 0.1500 d111.2161 9.8230 23.2974 d13 4.2190 3.7453 1.6711 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −9.34613 2 5 9.08938 3 12 25.75745

Numerical Example 23

The zoom lens system of Numerical Example 23 corresponds to Embodiment23 shown in FIG. 67. Table 67 shows the surface data of the zoom lenssystem of Numerical Example 23. Table 68 shows the aspherical data.Table 69 shows various data.

TABLE 67 (Surface data) Surface number r d nd vd Object surface ∞  1*34.18200 1.35000 1.88300 40.8  2* 4.69900 1.88700  3 7.07000 1.600001.92287 18.9  4 10.87800 Variable  5* 4.25100 2.00000 1.77250 49.6  68.92800 0.50000 1.64769 33.8  7 3.69800 0.48000  8 8.66500 0.500001.76183 26.5  9 4.04000 2.00000 1.60311 60.6 10 −12.32600 0.3000011(Diaphragm) ∞ Variable 12 26.45400 1.60000 1.60311 60.6 13 −48.99600Variable 14 ∞ 1.40000 1.51633 64.1 15 ∞ (BF) Image surface ∞

TABLE 68 (Aspherical data) Surface No. 1 K = 0.00000E+00, A4 =3.62205E−04, A6 = −5.63958E−06, A8 = 3.53569E−08, A10 = 0.00000E+00Surface No. 2 K = −1.52605E+00, A4 = 1.70369E−03, A6 = 2.17529E−05, A8 =−5.40577E−07, A10 = 8.14121E−09 Surface No. 5 K = −4.35512E−01, A4 =−8.44450E−07, A6 = 3.99899E−06, A8 = 0.00000E+00, A10 = 0.00000E+00

TABLE 69 (Various data) Zooming ratio 4.76804 Wide-angle MiddleTelephoto limit position limit Focal length 4.7145 10.4216 22.4791F-number 2.82795 4.62162 6.42143 View angle 39.1095 19.4169 9.1025 Imageheight 3.6000 3.6000 3.6000 Overall length 31.8271 31.1332 41.1670 oflens system BF 1.03932 1.00578 0.97275 d4 11.4400 3.4367 0.1500 d110.8955 8.6718 24.7468 d13 4.8353 4.4019 1.6804 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −10.05331 2 5 9.42654 3 1228.71276

Numerical Example 24

The zoom lens system of Numerical Example 24 corresponds to Embodiment24 shown in FIG. 70. Table 70 shows the surface data of the zoom lenssystem of Numerical Example 24. Table 71 shows the aspherical data.Table 72 shows various data.

TABLE 70 (Surface data) Surface number r d nd vd Object surface ∞  1*132.95400 1.35000 1.88300 40.8  2* 4.68700 1.46800  3 6.81900 1.600001.92287 18.9  4 11.04200 Variable  5* 4.17000 2.00000 1.77632 52.6  610.88700 0.50000 1.64619 31.8  7 3.66300 0.48000  8 8.27600 0.500001.76287 27.7  9 4.01800 2.00000 1.60281 56.0 10 −11.07600 0.3000011(Diaphragm) ∞ Variable 12 −90.89600 1.60000 1.60311 60.6 13 −17.48600Variable 14 ∞ 1.40000 1.51633 64.1 15 ∞ (BF) Image surface ∞

TABLE 71 (Aspherical data) Surface No. 1 K = 0.00000E+00, A4 =2.44936E−04, A6 = −4.54400E−06, A8 = 5.72566E−08, A10 = 0.00000E+00Surface No. 2 K = −1.48880E+00, A4 = 1.58237E−03, A6 = 2.31084E−06, A8 =−5.39884E−07, A10 = 4.21354E−08 Surface No. 5 K = −4.35869E−01, A4 =−7.86886E−05, A6 = −3.25838E−06, A8 = 0.00000E+00, A10 = 0.00000E+00

TABLE 72 (Various data) Zooming ratio 5.57548 Wide-angle MiddleTelephoto limit position limit Focal length 4.3036 10.4658 23.9944F-number 2.92255 5.16214 7.21745 View angle 43.8656 19.5147 8.6343 Imageheight 3.6000 3.6000 3.6000 Overall length 31.2161 30.7032 41.9501 oflens system BF 1.05074 1.06124 1.01753 d4 11.4400 3.5088 0.1500 d110.9832 10.2556 26.1962 d13 4.5442 2.6796 1.3884 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −8.59764 2 5 8.56522 3 12 35.60713

Numerical Example 25

The zoom lens system of Numerical Example 25 corresponds to Embodiment25 shown in FIG. 73. Table 73 shows the surface data of the zoom lenssystem of Numerical Example 25. Table 74 shows the aspherical data.Table 75 shows various data.

TABLE 73 (Surface data) Surface number r d nd vd Object surface ∞  1*54.53300 1.35000 1.88300 40.8  2* 4.96100 1.47200  3 6.67300 1.600001.92287 18.9  4 10.19200 Variable  5* 4.20800 2.00000 1.78129 58.0  69.60800 0.50000 1.64147 23.9  7 3.58500 0.48000  8 7.93100 0.500001.75881 27.4  9 4.13600 2.00000 1.60469 40.7 10 −14.12900 0.3000011(Diaphragm) ∞ Variable 12 −154.55700 1.60000 1.60311 60.6 13 −16.64500Variable 14 ∞ 1.40000 1.51633 64.1 15 ∞ (BF) Image surface ∞

TABLE 74 (Aspherical data) Surface No. 1 K = 0.00000E+00, A4 =2.53590E−04, A6 = −5.06029E−06, A8 = 7.20897E−08, A10 = 0.00000E+00Surface No. 2 K = −1.59957E+00, A4 = 1.57219E−03, A6 = 1.11451E−05, A8 =−8.91772E−07, A10 = 5.36076E−08 Surface No. 5 K = −4.33780E−01, A4 =2.73110E−06, A6 = 5.63913E−07, A8 = 0.00000E+00, A10 = 0.00000E+00

TABLE 75 (Various data) Zooming ratio 5.56401 Wide-angle MiddleTelephoto limit position limit Focal length 4.8460 10.4141 26.9631F-number 2.90201 4.44683 7.33626 View angle 39.6112 19.5730 7.6976 Imageheight 3.6000 3.6000 3.6000 Overall length 31.3839 28.2301 42.7099 oflens system BF 1.04922 1.08220 0.98344 d4 11.4400 2.8111 0.1500 d110.5529 2.7579 28.0785 d13 5.1398 8.3769 0.2960 Zoom lens unit data Lensunit Initial surface Focal length 1 1 −9.94113 2 5 9.09119 3 12 30.79516

The following Table 76 shows the corresponding values to the individualconditions in the zoom lens systems of Numerical Examples. Here, inTable 76, Y_(W) is defined as

an amount of movement in a direction perpendicular to the optical axisat the time of maximum blur compensation in the second lens unit with afocal length f_(W) of the entire system at a wide-angle limit, and

indicates a value obtained in a state that the zoom lens system is at awide-angle limit. That is, a corresponding value(Y_(W)/Y_(T))/(f_(W)/f_(T)) at the time of Y=Y_(W) (f=f_(W)) in thecondition formula (3) was obtained.

TABLE 76 (Values corresponding to conditions) Example Condition 1 2 3 45 6 7 8 9  (1) D₂/(I_(r) × Z²) 0.19 0.21 0.21 0.21 0.22 0.21 0.23 0.180.18  (2) Y_(W) 0.0397 0.0419 0.0419 0.0419 0.0419 0.0511 0.0479 0.04230.0430 Y_(T) 0.0820 0.0848 0.0838 0.0838 0.0838 0.1025 0.0935 0.08470.0860  (3) (Y_(W)/Y_(T))/(f_(W)/f_(T)) 0.096 0.103 0.105 0.105 0.1060.104 0.111 0.093 0.090  (4) (D_(2T) − D_(2W))/(I_(r) × Z²) 0.21 0.220.23 0.23 0.23 0.23 0.25 0.21 0.20  (5) f_(G1)/f_(G2) −1.19 −1.22 −1.20−1.20 −1.20 −1.20 −1.27 −1.20 −1.19  (6) f_(G1)/f_(G3) −0.57 −0.58 −0.57−0.57 −0.57 −0.58 −0.64 −0.58 −0.58  (7) f_(G2)/f_(G3) 0.48 0.48 0.480.48 0.48 0.48 0.50 0.48 0.49  (8) f_(G1)/f_(T) −0.53 −0.53 −0.52 −0.52−0.52 −0.52 −0.54 −0.46 −0.45  (9) f_(G2)/f_(T) 0.44 0.43 0.44 0.44 0.440.44 0.43 0.39 0.37 (10) f_(G3)/f_(T) 0.92 0.91 0.91 0.91 0.91 0.90 0.850.81 0.77 (11) (D_(1W) + D_(2W))/(D_(1T) + D_(2T)) 0.75 0.75 0.73 0.730.73 0.73 0.72 0.64 0.61 (12) (D_(2T) − D_(2W))/f_(W) 4.67 4.22 4.264.26 4.24 4.30 3.99 4.92 5.09 (13) (D_(2T) − D_(2W))/f_(T) 0.93 0.880.90 0.90 0.90 0.90 0.86 0.92 0.92 (14) D_(1T)/I_(r) 0.05 0.05 0.05 0.050.05 0.05 0.05 0.05 0.05 (15) (f_(W)/I_(r)) × (f_(W)/f_(T)) 0.22 0.250.25 0.25 0.25 0.25 0.29 0.23 0.22 (16) tan(ω_(W)) × Z 5.23 4.59 4.534.51 4.51 4.58 3.76 5.09 5.09 (17) |f_(W) × f_(G1)|/I_(r) ² 3.23 3.633.60 3.61 3.61 3.60 4.56 3.63 3.72 (18) (f_(W) · f_(G2))/I_(r) ² 2.732.99 3.01 3.01 3.02 2.99 3.59 3.04 3.12 (19) (D_(G1) + D_(G2) +D_(G3))/f_(T) 0.52 0.50 0.50 0.50 0.50 0.48 0.46 0.45 0.42 (20) (F_(W) ×F_(T))/Z 3.54 3.82 3.75 3.76 3.77 3.68 3.86 3.76 3.86 (21) L_(T)/(I_(r)× Z) 1.95 2.06 2.09 2.09 2.10 2.04 2.19 1.91 1.90 (22) (D_(G2) +(D_(G2A)))/(D_(G2A)) 12.92 12.93 12.93 12.93 12.93 12.67 13.49 12.9312.93 (23) f_(L2)/f_(G1) −1.59 −1.32 −1.41 −1.53 −1.53 −1.53 −1.31 −1.52−1.51 (24) R_(2F)/f_(T) 0.44 0.37 0.43 0.42 0.42 0.42 0.38 0.37 0.35(25) R_(2R)/f_(T) 0.82 0.71 0.80 0.80 0.80 0.80 0.74 0.71 0.67 (26)f_(L2)/f_(T) 0.84 0.69 0.74 0.80 0.80 0.80 0.71 0.71 0.67 (27)f_(L3)/f_(G2) 0.68 0.77 0.68 0.68 0.64 0.68 0.65 0.67 0.67 (28)f_(G2a)/f_(G2b) — — — — — — — — — (29) (1 − m_(2T)) × m_(3T) 2.70 2.702.72 2.71 2.71 2.71 2.64 3.04 3.14 (30) m_(2T)/m_(2W) 4.63 4.47 4.384.38 4.39 4.40 4.13 4.43 4.50 (31) (1 − m_(2T)/m_(2W)) × (m_(3T)/m_(3W))−3.94 −3.72 −3.67 −3.66 −3.66 −3.70 −3.49 −4.15 −4.30 (32) (1 − m_(2W))× m_(3W) 1.11 1.14 1.14 1.14 1.15 1.14 1.12 1.14 1.14 f_(T)/f_(W) 5.024.79 4.75 4.74 4.73 4.78 4.61 5.36 5.53 ω_(W) 46.160 43.774 43.65843.523 43.630 43.786 39.200 43.535 42.612 Example Condition 10 11 12 1314 15 16 17 18  (1) D₂/(I_(r) × Z²) 0.24 0.19 0.20 0.23 0.17 0.21 0.190.19 0.24  (2) Y_(W) 0.0524 0.0413 0.0426 0.0476 0.0404 0.0501 0.04580.0453 0.0507 Y_(T) 0.1038 0.0829 0.0854 0.0933 0.0841 0.1016 0.09720.0966 0.0974  (3) (Y_(W)/Y_(T))/(f_(W)/f_(T)) 0.107 0.106 0.107 0.1090.085 0.105 0.095 0.095 0.115  (4) (D_(2T) − D_(2W))/(I_(r) × Z²) 0.250.21 0.22 0.25 0.19 0.23 0.20 0.20 0.27  (5) f_(G1)/f_(G2) −1.37 −1.27−1.27 −1.27 −1.19 −1.42 −1.40 −1.40 −1.30  (6) f_(G1)/f_(G3) −0.59 −0.65−0.58 −0.63 −0.48 −0.70 −0.68 −0.71 −0.67  (7) f_(G2)/f_(G3) 0.43 0.510.46 0.49 0.41 0.49 0.49 0.51 0.51  (8) f_(G1)/f_(T) −0.49 −0.59 −0.57−0.55 −0.44 −0.55 −0.54 −0.55 −0.56  (9) f_(G2)/f_(T) 0.36 0.47 0.450.44 0.37 0.39 0.39 0.40 0.43 (10) f_(G3)/f_(T) 0.83 0.92 0.98 0.88 0.910.80 0.79 0.78 0.84 (11) (D_(1W) + D_(2W))/(D_(1T) + D_(2T)) 0.70 0.810.80 0.72 0.64 0.80 0.84 0.86 0.70 (12) (D_(2T) − D_(2W))/f_(W) 3.574.21 4.06 4.12 5.18 3.54 3.78 3.78 3.94 (13) (D_(2T) − D_(2W))/f_(T)0.76 0.89 0.87 0.88 0.92 0.76 0.76 0.76 0.87 (14) D_(1T)/I_(r) 0.05 0.050.05 0.05 0.05 0.05 0.05 0.05 0.05 (15) (f_(W)/I_(r)) × (f_(W)/f_(T))0.33 0.24 0.25 0.28 0.21 0.30 0.26 0.26 0.31 (16) tan(ω_(W)) × Z 3.364.54 4.10 3.67 4.97 3.64 4.29 4.38 3.38 (17) |f_(W) × f_(G1)|/I_(r) ²5.79 3.45 3.78 4.44 3.50 5.23 4.54 4.42 4.95 (18) (f_(W) · f_(G2))/I_(r)² 4.22 2.72 2.97 3.49 2.95 3.68 3.25 3.16 3.80 (19) (D_(G1) + D_(G2) +D_(G3))/f_(T) 0.37 0.51 0.48 0.44 0.40 0.36 0.37 0.38 0.42 (20) (F_(W) ×F_(T))/Z 4.61 3.82 3.83 3.89 3.88 3.82 3.48 3.56 4.16 (21) L_(T)/(I_(r)× Z) 2.22 1.89 1.97 2.15 1.85 2.05 1.91 1.89 2.23 (22) (D_(G2) +(D_(G2A)))/(D_(G2A)) 17.83 16.07 16.07 16.07 16.07 4.62 4.59 4.56 16.07(23) f_(L2)/f_(G1) −1.80 −1.58 −1.54 −1.47 −1.74 −1.33 −1.44 −1.44 −1.41(24) R_(2F)/f_(T) 0.27 0.43 0.41 0.37 0.34 0.34 0.35 0.36 0.36 (25)R_(2R)/f_(T) 0.37 0.72 0.68 0.62 0.56 0.57 0.58 0.60 0.60 (26)f_(L2)/f_(T) 0.88 0.94 0.89 0.81 0.76 0.74 0.77 0.80 0.79 (27)f_(L3)/f_(G2) 0.67 0.56 0.55 0.53 0.59 0.78 0.79 0.79 0.50 (28)f_(G2a)/f_(G2b) — — — — — — — — — (29) (1 − m_(2T)) × m_(3T) 2.86 2.512.58 2.61 3.17 2.61 2.65 2.59 2.58 (30) m_(2T)/m_(2W) 4.41 4.05 4.094.12 4.84 4.35 4.74 4.74 3.95 (31) (1 − m_(2T)/m_(2W)) × (m_(3T)/m_(3W))−3.66 −3.55 −3.53 −3.53 −4.48 −3.61 −3.92 −3.90 −3.39 (32) (1 − m_(2W))× m_(3W) 1.20 1.07 1.11 1.10 1.17 1.13 1.13 1.11 1.09 f_(T)/f_(W) 4.734.71 4.67 4.66 5.64 4.69 4.97 4.95 4.54 ω_(W) 35.441 43.934 41.31438.201 41.362 37.767 40.763 41.506 36.651 Example Condition 19 20 21 2223 24 25  (1) D₂/(I_(r) × Z²) 0.23 0.22 0.21 0.24 0.25 0.20 0.20  (2)Y_(W) 0.0480 0.0500 0.0334 0.0373 0.0408 0.0341 0.0403 Y_(T) 0.09400.0989 0.0650 0.0707 0.0762 0.0678 0.0775  (3)(Y_(W)/Y_(T))/(f_(W)/f_(T)) 0.110 0.089 0.107 0.110 0.112 0.090 0.093 (4) (D_(2T) − D_(2W))/(I_(r) × Z²) 0.25 0.24 0.24 0.27 0.29 0.23 0.25 (5) f_(G1)/f_(G2) −1.28 −1.20 −1.01 −1.03 −1.07 −1.00 −1.09  (6)f_(G1)/f_(G3) −0.64 −0.63 −0.33 −0.36 −0.35 −0.24 −0.32  (7)f_(G2)/f_(G3) 0.50 0.52 0.33 0.35 0.33 0.24 0.30  (8) f_(G1)/f_(T) −0.56−0.43 −0.46 −0.46 −0.45 −0.36 −0.37  (9) f_(G2)/f_(T) 0.44 0.36 0.460.44 0.42 0.36 0.34 (10) f_(G3)/f_(T) 0.87 0.68 1.40 1.26 1.28 1.48 1.14(11) (D_(1W) + D_(2W))/(D_(1T) + D_(2T)) 0.72 0.52 0.60 0.54 0.50 0.470.42 (12) (D_(2T) − D_(2W))/f_(W) 4.13 5.56 5.10 5.17 5.06 5.86 5.68(13) (D_(2T) − D_(2W))/f_(T) 0.89 0.98 1.06 1.08 1.06 1.05 1.02 (14)D_(1T)/I_(r) 0.05 0.05 0.04 0.04 0.04 0.04 0.04 (15) (f_(W)/I_(r)) ×(f_(W)/f_(T)) 0.28 0.24 0.23 0.25 0.27 0.21 0.24 (16) tan(ω_(W)) × Z3.89 4.35 5.06 4.54 3.88 5.36 4.60 (17) |f_(W) × f_(G1)|/I_(r) ² 4.474.54 2.61 3.08 3.66 2.86 3.72 (18) (f_(W) · f_(G2))/I_(r) ² 3.50 3.772.57 2.99 3.43 2.84 3.40 (19) (D_(G1) + D_(G2) + D_(G3))/f_(T) 0.44 0.340.62 0.59 0.53 0.48 0.43 (20) (F_(W) × F_(T))/Z 3.87 4.22 3.57 3.72 3.813.78 3.83 (21) L_(T)/(I_(r) × Z) 2.17 2.16 2.15 2.31 2.40 2.09 2.13 (22)(D_(G2) + (D_(G2A)))/(D_(G2A)) 16.07 16.07 19.27 19.27 19.27 19.27 19.27(23) f_(L2)/f_(G1) −1.48 −1.50 −1.87 −1.95 −1.81 −1.90 −1.73 (24)R_(2F)/f_(T) 0.38 0.29 0.38 0.34 0.31 0.28 0.25 (25) R_(2R)/f_(T) 0.620.49 0.64 0.53 0.48 0.46 0.38 (26) f_(L2)/f_(T) 0.83 0.64 0.86 0.89 0.810.68 0.64 (27) f_(L3)/f_(G2) 0.51 0.50 0.94 0.94 0.94 0.90 0.91 (28)f_(G2a)/f_(G2b) — — 2.35 2.51 2.33 2.20 2.33 (29) (1 − m_(2T)) × m_(3T)2.58 3.13 3.02 3.03 3.09 3.70 3.64 (30) m_(2T)/m_(2W) 4.12 4.89 4.334.23 4.14 5.03 4.61 (31) (1 − m_(2T)/m_(2W)) × (m_(3T)/m_(3W)) −3.52−4.51 −3.69 −3.65 −3.62 −4.47 −4.36 (32) (1 − m_(2W)) × m_(3W) 1.09 1.091.22 1.20 1.21 1.32 1.26 f_(T)/f_(W) 4.64 5.67 4.80 4.79 4.77 5.58 5.56ω_(W) 39.994 37.452 46.521 43.472 39.109 43.866 39.611

INDUSTRIAL APPLICABILITY

The zoom lens system according to the present invention is applicable toa digital input device such as a digital camera, a mobile telephone, aPDA (Personal Digital Assistance), a surveillance camera in asurveillance system, a Web camera or a vehicle-mounted camera. Inparticular, the zoom lens system according to the present invention issuitable for a photographing optical system where high image quality isrequired like in a digital camera.

1. A zoom lens system having a plurality of lens units each composed ofat least one lens element and, in order from an object side to an imageside, comprising: a first lens unit having negative optical power andcomposed of two lens elements; a second lens unit having positiveoptical power; and a third lens unit having positive optical power,wherein in zooming from a wide-angle limit to a telephoto limit duringimage taking, the individual lens units are moved along an optical axissuch that an interval between the first lens unit and the second lensunit should decrease and that an interval between the second lens unitand the third lens unit should increase, so that magnification change isachieved, and wherein on the image side relative to the second lensunit, an aperture diaphragm is arranged that moves along the opticalaxis integrally with the second lens unit during zooming.
 2. The zoomlens system as claimed in claim 1, wherein the first lens unit, in orderfrom the object side to the image side, comprises: a lens element havingnegative optical power; and a meniscus lens element having positiveoptical power with the convex surface facing the object side.
 3. Thezoom lens system as claimed in claim 1, wherein the first lens unitincludes at least one lens element having an aspheric surface.
 4. Thezoom lens system as claimed in claim 1, wherein the first lens unitincludes at least two aspheric surfaces.
 5. The zoom lens system asclaimed in claim 1, wherein the third lens unit is composed of one lenselement.
 6. The zoom lens system as claimed in claim 5, wherein one lenselement of the third lens unit includes an aspheric surface.
 7. The zoomlens system as claimed in claim 1, wherein the second lens unit iscomposed of three lens elements.
 8. The zoom lens system as claimed inclaim 1, wherein the second lens unit is composed of four lens elements.9. The zoom lens system as claimed in claim 1, wherein the second lensunit moves in a direction perpendicular to the optical axis.
 10. Thezoom lens system as claimed in claim 9, wherein the entire systemsatisfies the following conditions (2) and (3):Y_(T)>Y  (2)0.05<(Y/Y _(T))/(f _(T) /f)<0.60  (3) (here, Z=f_(T)/f_(W)>4.0 andω_(W)>35) where, f is a focal length of the entire system, f_(T) is afocal length of the entire system at a telephoto limit, Y is an amountof movement in a direction perpendicular to the optical axis at the timeof maximum blur compensation in the second lens unit with a focal lengthf of the entire system, Y_(T) is an amount of movement in a directionperpendicular to the optical axis at the time of maximum blurcompensation in the second lens unit with a focal length f_(T) of theentire system at a telephoto limit, f_(W) is a focal length of theentire system at a wide-angle limit, and ω_(W) is a half value (°) ofthe maximum view angle at a wide-angle limit.
 11. An imaging devicecapable of outputting an optical image of an object as an electric imagesignal, comprising: a zoom lens system that forms the optical image ofthe object; and an image sensor that converts the optical image formedby the zoom lens system into the electric image signal, wherein the zoomlens system has a plurality of lens units each composed of at least onelens element and, in order from an object side to an image side,comprises: a first lens unit having negative optical power and composedof two lens elements; a second lens unit having positive optical power;and a third lens unit having positive optical power, wherein in zoomingfrom a wide-angle limit to a telephoto limit during image taking, theindividual lens units are moved along an optical axis such that aninterval between the first lens unit and the second lens unit shoulddecrease and that an interval between the second lens unit and the thirdlens unit should increase, so that magnification change is achieved, andwherein on the image side relative to the second lens unit, an aperturediaphragm is arranged that moves along the optical axis integrally withthe second lens unit during zooming.
 12. A camera for converting anoptical image of an object into an electric image signal and thenperforming at least one of displaying and storing of the converted imagesignal, comprising an imaging device including a zoom lens system thatforms the optical image of the object and an image sensor that convertsthe optical image formed by the zoom lens system into the electric imagesignal, wherein the zoom lens system has a plurality of lens units eachcomposed of at least one lens element and, in order from an object sideto an image side, comprises: a first lens unit having negative opticalpower and composed of two lens elements; a second lens unit havingpositive optical power; and a third lens unit having positive opticalpower, wherein in zooming from a wide-angle limit to a telephoto limitduring image taking, the individual lens units are moved along anoptical axis such that an interval between the first lens unit and thesecond lens unit should decrease and that an interval between the secondlens unit and the third lens unit should increase, so that magnificationchange is achieved, and wherein on the image side relative to the secondlens unit, an aperture diaphragm is arranged that moves along theoptical axis integrally with the second lens unit during zooming.